Planar type micromachined probe with low uncertainty at low frequencies

Kim, Jung Mu; Cho, Sungjoon; Kim, Namgon; Yoon, Jong‐Gul; Cho, Jeiwon; Cheon, Changyul; Kwon, Youngwoo; Kim, Yong Kweon

doi:10.1016/j.sna.2007.04.028

Cited by 12 publications

(10 citation statements)

References 8 publications

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“…Among these, the difference in the dielectric losses between tumor and normal tissues is most important because of the well-known fact that the temperature rise by microwave ablation is a function of the dielectric loss of the material. 19 As shown in Figure 6, the large difference of dielectric loss is observed in the low-frequency band (<1 GHz) as well as in the high-frequency band (15)(16)(17)(18)(19)(20)(21)(22)(23)(24), which may suggest that the low-frequency microwave ($ 0.9 GHz) can also be a good candidate for efficient heat generation (Fig. 6).…”

Section: Discussionmentioning

confidence: 94%

“…However, as the applicator of our work was realized with a planar two-dimensional structure realized with multilayer printed circuit boards, it can easily lend itself to further size reduction by using more sophisticated fabrication technology such as micromachining. For example, a miniaturized planar probe with very similar structure has been demonstrated by the authors using micromachining, 20 where the width of the applicator was less than 0.8 mm and the thickness was only 0.52 mm, which is suitable for a percutaneous approach. In principle, the entire ablation system can be realized with low-power electronics and integrated into a size suitable for hand-held applications, making the system very compact and cost-effective.…”

Section: Discussionmentioning

confidence: 99%

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High‐frequency microwave ablation method for enhanced cancer treatment with minimized collateral damage

Yoon

Cho

Kim

et al. 2011

Intl Journal of Cancer

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To overcome the limits of conventional microwave ablation, a new frequency spectrum above 6 GHz has been explored for low-power and low collateral damage ablation procedure. A planar coaxial probe-based applicator, suitable for easy insertion into the human body, was developed for our study to cover a wideband frequency up to 30 GHz. Thermal ablations with small input power (1-3 W) at various microwave frequencies were performed on nude mice xenografted with human breast cancer. Comparative study of ablation efficiencies revealed that 18-GHz microwave results in the largest difference in the temperature rise between cancer and normal tissues as well as the highest ablation efficiency, reaching 20 times that of 2 GHz. Thermal profile study on the composite region of cancer and fat also showed significantly reduced collateral damage using 18 GHz. Application of low-power (1 W) 18-GHz microwave on the nude mice xenografted with human breast cancer cells resulted in recurrence-free treatment. The proposed microwave ablation method can be a very effective process to treat small-sized tumor with minimized invasiveness and collateral damages.Breast cancer is a major threat to women's health psychologically as well as physically. 1 Despite the high potential of fatality, most women show reluctance for large-scale breast removal due to cosmetic concerns, which brings about the need for local surgical control. For this reason, minimally invasive techniques to achieve better local surgical control have collected extensive attention as a possible first-line treatment in lieu of conservative breast surgery procedures such as lumpectomy. 2,3 Among several alternative methods, microwave ablation entails many benefits in comparison with the others such as laser ablation, cryoablation and ethanol ablation. [4][5][6][7][8] Microwave ablation method is much safer and easily manageable 9 and can, in principle, offer material-specific responsiveness, where tissues with high water content such as cancer are preferentially heated and damaged. 10,11 This characteristic of microwaves makes microwave ablation well suited for local treatment of early stage of breast cancer. So far, the frequencies used in the existing microwave ablation systems have been limited to the low-frequency spectrum such as 915 MHz or 2.4 GHz. Because of the inherent low radiation efficiency, very high microwave input power of several tens of Watts is required at these frequencies, thus greatly increasing the cost and size of the equipment. 12 Moreover, because of the self-heating of the applicator by the excessive microwave power, additional means for cooling the applicator are required to avoid the damage of healthy tissues near the passage of the applicator. 13 Besides, the conventional low-frequency spectrum ablation has poor material selectivity when compared to the alternative high-frequency spectrum proposed in our work.To overcome the limitations of the existing microwave ablation methods, we have investigated the properties of microwaves up to 30 GHz wit...

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Section: Discussionmentioning

confidence: 94%

Section: Discussionmentioning

confidence: 99%

High‐frequency microwave ablation method for enhanced cancer treatment with minimized collateral damage

Yoon

Cho

Kim

et al. 2011

Intl Journal of Cancer

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“…The planar probe has an aperture defined on its broadside, thereby providing flexibility of varying the shape and size of the aperture according to specific medical needs. The planar implementation of the probe has many advantages including low production cost, simple fabrication, and nondestructive nature, which can be maximized by using a MEMS technology [7], [8].…”

Section: Active Integrated Probesmentioning

confidence: 99%

Microwave active integrated probes for biomedical applications

Kım

Kim

Hwang

et al. 2013

2013 Asia-Pacific Microwave Conference Proceedings (APMC)

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This paper introduces recently developed active integrated probes for biomedical applications. To realize broadband cancer detection and low-power cancer ablation, planar-type coaxial probes have been integrated with active circuits for measurement and microwave generation, respectively. A multi-state reflectometer (MSR) is employed for cancer detection based on broadband permittivity characteristics. Also, to achieve microwave hyperthermia, a Kuband microwave source is integrated on the probe platform. Each active integrated probe is implemented on a single silicon platform using Microelectromechanical Systems (MEMS) and monolithic microwave integrated circuit (MMIC) technologies for miniaturization and integration. Through the experiments, the feasibilities of the active integrated probes for microwave cancer detection and ablation have been validated.Index Terms -Active probe, complex permittivity, hyperthermia, microelectromechanical systems (MEMS), multistate reflectometer, open-ended coaxial probe.

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“…The proposed RF MEMS probe array system consists of an RF MEMS SP3T silicon switch, which is well known as a type of RF MEMS switch with good reliability [7,8], and RF MEMS transmission lines with three planar-type apertures [9]. As the three probes have an identical structure, the purpose of this probe array system is to obtain a spatial scan.…”

Section: Rf Mems Probe Array Systemmentioning

confidence: 99%

“…The crosssection and side view of the proposed transmission line are shown in figure 4. A planar-type aperture is used as the aperture of the probe array, because there is low uncertainty with this at low frequencies [9].…”

Section: Micromachined Transmission Line With Planar-type Aperturementioning

confidence: 99%

A hybrid RF MEMS probe array system with a SP3T RF MEMS silicon switch for permittivity measurement

Kim¹,

Cheon²,

Kwon³

et al. 2008

J. Micromech. Microeng.

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This paper reports a hybrid RF MEMS probe array system for permittivity measurements. A single-pole triple-throw (SP3T) RF MEMS silicon switch and a novel surface micromachined transmission line with three planar apertures were designed, fabricated and measured. These MEMS devices were connected using wire bonding and bond wire effects were cancelled as a consequence of in-liquid calibration of the whole system. A permittivity measurement of 0.9% saline was made by operating each RF MEMS silicon switch. The measured result showed good agreement with the reference value from the Cole–Cole equation up to 20 GHz. This result shows the feasibility of the proposed hybrid RF MEMS probe array system for permittivity measurements.

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Planar type micromachined probe with low uncertainty at low frequencies

Cited by 12 publications

References 8 publications

High‐frequency microwave ablation method for enhanced cancer treatment with minimized collateral damage

High‐frequency microwave ablation method for enhanced cancer treatment with minimized collateral damage

Microwave active integrated probes for biomedical applications

A hybrid RF MEMS probe array system with a SP3T RF MEMS silicon switch for permittivity measurement

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