Shaping and resizing of multifed slot radiators used in conformal microwave antenna arrays for hyperthermia treatment of large superficial diseases

Maccarini, Paolo F.; Arunachalam, Kavitha; Juang, Titania; Luca, Valéria De; Rangarao, Sneha; Neumann, Daniel; Martins, Carlos D.; Craciunescu, Oana; Stauffer, Paul R.

doi:10.1109/iceaa.2009.5297299

Cited by 6 publications

(5 citation statements)

References 2 publications

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“…The stacked phantom consisted of a 5 mm fat layer on top, a 28 mm muscle phantom in the middle and a 5 mm fatlayer at the bottom. Heating was done with a single Dual Concentric Conductor (DCC) antenna [13, 14] at 915 MHz through a bolus of circulating water. The input power to the top antenna was approximately 20 W at 915 MHz.…”

Section: Resultsmentioning

confidence: 99%

Design of Medical Radiometer Front-End for Improved Performance

Klemetsen¹,

Birkelund²,

Jacobsen³

et al. 2011

PIER B

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We have investigated the possibility of building a singleband Dicke radiometer that is inexpensive, small-sized, stable, highly sensitive, and which consists of readily available microwave components. The selected frequency band is at 3.25–3.75 GHz which provides a reasonable compromise between spatial resolution (antenna size) and sensing depth for radiometry applications in lossy tissue. Foreseen applications of the instrument are non-invasive temperature monitoring for breast cancer detection and temperature monitoring during heating. We have found off-the-shelf microwave components that are sufficiently small (< 5 mm × 5 mm) and which offer satisfactory overall sensitivity. Two different Dicke radiometers have been realized: one is a conventional design with the Dicke switch at the front-end to select either the antenna or noise reference channels for amplification. The second design places a matched pair of low noise amplifiers in front of the Dicke switch to reduce system noise figure. Numerical simulations were performed to test the design concepts before building prototype PCB front-end layouts of the radiometer. Both designs provide an overall power gain of approximately 50 dB over a 500 MHz bandwidth centered at 3.5 GHz. No stability problems were observed despite using triple-cascaded amplifier configurations to boost the thermal signals. The prototypes were tested for sensitivity after calibration in two different water baths. Experiments showed superior sensitivity (36% higher) when implementing the low noise amplifier before the Dicke switch (close to the antenna) compared to the other design with the Dicke switch in front. Radiometer performance was also tested in a multilayered phantom during alternating heating and radiometric reading. Empirical tests showed that for the configuration with Dicke switch first, the switch had to be locked in the reference position during application of microwave heating to avoid damage to the active components (amplifiers and power meter). For the configuration with a low noise amplifier up front, damage would occur to the active components of the radiometer if used in presence of the microwave heating antenna. Nevertheless, this design showed significantly improved sensitivity of measured temperatures and merits further investigation to determine methods of protecting the radiometer for amplifier first front ends.

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Section: Resultsmentioning

confidence: 99%

Design of Medical Radiometer Front-End for Improved Performance

Klemetsen¹,

Birkelund²,

Jacobsen³

et al. 2011

PIER B

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“…The average depth of the kidney was measured as 3.5cm to the renal pelvis from the skin. EM computer simulations of the 915 MHz DCC antenna indicated that multiple warming antennas minimized skin and intervening tissue warming and maximized the warming of urine in the bladder [7, 8]. A DCC antenna array with two 3 × 3 cm square elements operating incoherently at 915 MHz was found to be the best for bladder warming through a thin layer (7–10mm) of deionized waterbolus at room temperature [9].…”

Section: Resultsmentioning

confidence: 99%

“…Due to smaller urine volume (75 mL) in the experimental setup, a modified version of the single square Dual Concentric Conductor [7, 8] microwave antenna (5 cm wide) was used for phantom studies to deposit microwave power inside the 4.22 cm wide urine phantom at depth. Thus, power was applied to a single element DCC test antenna that was directed into the multilayer waterbolus-fat-muscle load and into the urine filled bladder (75 ml).…”

Section: Methodsmentioning

confidence: 99%

Non-invasive vesicoureteral reflux detection: Heating risk studies for a new device

Snow

Arunachalam

Luca³

et al. 2011

Journal of Pediatric Urology

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OBJECTIVE A novel non-invasive device is being developed to warm bladder urine and to measure kidney temperature to detect vesicoureteral reflux (VUR). MATERIALS AND METHODS Microwave antennas focus energy within the bladder. Phantom experiments measured the results. The heating protocol was optimized in an in vivo porcine model. The heating protocol safety performed once, twice and three times consecutively was investigated in three pigs followed by pathologic examinations. RESULTS Computer simulations showed a dual concentric conductor square slot antenna the best. Phantom studies revealed this antenna easily heated a bladder phantom without over heating intervening layers. In vivo a bladder heating protocol of 3 minutes with 30 W each to 2 adjacent antennas 45sec on 15sec off followed by 15 minutes of 15sec on and 45sec off was sufficient. When pigs were heated once, twice and three times with this heating protocol, pathologic examination of all tissues in the heated area showed no thermal changes. More intensive heating in the animal may have resulted in damage to muscle fibers in the anterior abdominal wall. CONCLUSION Selective warming of bladder urine was successfully demonstrated in phantom and animals. Localized heating for this novel VUR device requires low power levels and should be safe for humans.

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“…Furthermore, superficial antennas with various effective field sizes allowing adequate treatment of both small and larger tumor areas have been developed. This has resulted in clear progress in the quality of superficial heating equipment [310][311][312][313][314][315].…”

Section: Clinical Applications Of Intraluminal Hyperthermia and Hivecmentioning

confidence: 99%

Heating technology for malignant tumors: a review

Kok

Cressman

Ceelen

et al. 2020

International Journal of Hyperthermia

257

188

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The therapeutic application of heat is very effective in cancer treatment. Both hyperthermia, i.e., heating to 39-45 C to induce sensitization to radiotherapy and chemotherapy, and thermal ablation, where temperatures beyond 50 C destroy tumor cells directly are frequently applied in the clinic. Achievement of an effective treatment requires high quality heating equipment, precise thermal dosimetry, and adequate quality assurance. Several types of devices, antennas and heating or power delivery systems have been proposed and developed in recent decades. These vary considerably in technique, heating depth, ability to focus, and in the size of the heating focus. Clinically used heating techniques involve electromagnetic and ultrasonic heating, hyperthermic perfusion and conductive heating. Depending on clinical objectives and available technology, thermal therapies can be subdivided into three broad categories: local, locoregional, or whole body heating. Clinically used local heating techniques include interstitial hyperthermia and ablation, high intensity focused ultrasound (HIFU), scanned focused ultrasound (SFUS), electroporation, nanoparticle heating, intraluminal heating and superficial heating. Locoregional heating techniques include phased array systems, capacitive systems and isolated perfusion. Whole body techniques focus on prevention of heat loss supplemented with energy deposition in the body, e.g., by infrared radiation. This review presents an overview of clinical hyperthermia and ablation devices used for local, locoregional, and whole body therapy. Proven and experimental clinical applications of thermal ablation and hyperthermia are listed. Methods for temperature measurement and the role of treatment planning to control treatments are discussed briefly, as well as future perspectives for heating technology for the treatment of tumors.

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Shaping and resizing of multifed slot radiators used in conformal microwave antenna arrays for hyperthermia treatment of large superficial diseases

Cited by 6 publications

References 2 publications

Design of Medical Radiometer Front-End for Improved Performance

Design of Medical Radiometer Front-End for Improved Performance

Non-invasive vesicoureteral reflux detection: Heating risk studies for a new device

Heating technology for malignant tumors: a review

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