Evolution of a microwave instrument for analysis and thermal ablation of organic tissue

Puentes, Margarita; Schüßler, Martin; Damm, Christian; Jakoby, Rolf

doi:10.1109/eumc.2014.6986425

Cited by 4 publications

(2 citation statements)

References 11 publications

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“…The main challenge concerning the design of a minimally invasive applicator is given by the size limitation that the sensor can be integrated in a needle-like operation tool. The general functional principle was previously proven by using circular SRR with a larger dimension in the range of several cm [ 17 ]. By simply decreasing the size of the SRR, the operating frequency increases significantly.…”

Section: Discussionmentioning

confidence: 99%

Planar Microwave Sensor for Theranostic Therapy of Organic Tissue Based on Oval Split Ring Resonators

Reimann

Puentes

Maasch

et al. 2016

Sensors

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Microwave sensors in medical environments play a significant role due to the contact-less and non-invasive sensing mechanism to determine dielectric properties of tissue. In this work, a theranostic sensor based on Split Ring Resonators (SRRs) is presented that provides two operation modes to detect and treat tumor cells, exemplary in the liver. For the detection mode, resonance frequency changes due to abnormalities are evaluated, and in the treatment mode, microwave ablation is performed. The planar sensor structure can be integrated into a needle like a surgery tool that evokes challenges concerning size limitations and biocompatibility. To meet the size requirements and provide a reasonable operating frequency, properties of oval shaped SRRs are investigated. By elongating the radius of the SRR in one direction, the resonance frequency can be decreased significantly compared to circular SRR by a factor of two below 12 GHz. In order to validate the detection and treatment characteristics of the sensor, full wave simulations and measurements are examined. Clear resonance shifts are detected for loading the sensor structures with phantoms mimicking healthy and malignant tissue. For treatment mode evaluation, ex vivo beef liver tissue was ablated leading to a lesion zone 1.2 cm × 1 cm × 0.3 cm with a three minute exposure of maximum 2.1 W.

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Section: Discussionmentioning

confidence: 99%

Planar Microwave Sensor for Theranostic Therapy of Organic Tissue Based on Oval Split Ring Resonators

Reimann

Puentes

Maasch

et al. 2016

Sensors

Self Cite

View full text Add to dashboard Cite

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“…NE of the key requirements in medical, biological, and chemical applications is the combination of the microwave heating and sensing techniques, where the same microwave resonator is used for heating and characterization of the sample at the same time. In [1] and [2], a planar structure based on a split ring resonator was used to design dual sensor which can be operated for sensing the dielectric properties of the organic tissue as well as for executing thermal ablation therapy. The simultaneous sensing and heating of individual nanoliter-sized droplets in microfluidic devices was presented in [3], where an electrically small resonator was able to distinguish between materials with different electrical properties.…”

Section: Introductionmentioning

confidence: 99%

Novel Variable Coupling Technique for Microwave Liquid Heating and Sensing

Abduljabar

Choi

Porch

2018

2018 18th Mediterranean Microwave Symposium (MMS)

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A simple, new, variable-coupling technique is presented in this paper. The aim of the design is to optimize the coupling between a microwave source and a microwave resonator in which the resonator (in our case a cylindrical cavity resonator, for demonstration purposes) can be used either as a microwave applicator or sensor. Our technique involves the inclusion of a variable capacitor in the coupling loop that terminates the cavity's coaxial feedline.. For proof-of-concept, the proposed approach was applied to a 2.45 GHz TM 010 cylindrical cavity for heating and sensing of several types of solvents. The experimental results show the capability to reach any coupling value when the resonator is loaded with various liquid samples by adjusting the value of the terminating capacitor. Hence, the critical coupling condition can be achieved by electronic, rather than mechanical, means.

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Theranostic microwave applicator suitable for minimal invasive therapy of malignant tissue

Reimann

Puentes

Schusler

et al. 2016

2016 38th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC)

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A microwave applicator is presented that realizes the theranostic approach by providing two operation modes to detect and treat tumor cells, exemplary in the liver. The tool is based on a planar sensor structure with Split Ring Resonators (SRR) as key elements. For the detection, changes in dielectric properties caused by tissue abnormalities are evaluated by analyzing shifts in the resonance frequency of the SRR. For the treatment mode, the input power is amplified to the specific resonance frequency and microwave ablation is performed. The device is designed to fit into a needle like operation tool for minimal invasive therapies. From this requirement, challenges concerning size limitation, packaging, and bio compatibility can be derived. Therefore, novel shapes of the SRR and substrate materials are investigated by full wave simulations and measurements. Material models and phantoms mimicking dielectric properties of healthy and malignant tissue are introduced. Clear resonance shifts of 100 MHz are detected for loading the sensor with corresponding phantoms. In order to examine the treatment mode characteristics, thermal simulations and measurements exhibit a significant temperature increase up to 62 °C for an input power of 500 mW.

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Evolution of a microwave instrument for analysis and thermal ablation of organic tissue

Cited by 4 publications

References 11 publications

Planar Microwave Sensor for Theranostic Therapy of Organic Tissue Based on Oval Split Ring Resonators

Planar Microwave Sensor for Theranostic Therapy of Organic Tissue Based on Oval Split Ring Resonators

Novel Variable Coupling Technique for Microwave Liquid Heating and Sensing

Theranostic microwave applicator suitable for minimal invasive therapy of malignant tissue

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