Wireless Interrogation of Implantable SAW Sensors

Zou, Longfang; McLeod, Chris; Bahmanyar, Mohammad Reza

doi:10.1109/tbme.2019.2937224

Cited by 19 publications

(11 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Moreover, the penetration depth for cardiac implant applications can vary depending on the implant type and the patient’s specific requirements. Generally, implants are placed between 0.5 and 3 cm below the skin, but some may be placed up to 5 cm below the skin [ 35 ]. Therefore, the analysis of the penetration depth of biological tissues is of paramount importance through different biological tissues and hence to choose an optimal frequency band for cardiac wireless communication.…”

Section: Methodsmentioning

confidence: 99%

Optimizing Cardiac Wireless Implant Communication: A Feasibility Study on Selecting the Frequency and Matching Medium

Amin

Rehman

Farooq

et al. 2023

Sensors

View full text Add to dashboard Cite

Cardiac wireless implantable medical devices (CWIMD) have brought a paradigm shift in monitoring and treating various cardiac conditions, including heart failure, arrhythmias, and hypertension. One of the key elements in CWIMD is the implant antenna which uses radio frequency (RF) technology to wirelessly communicate and transmit data to external devices. However, wireless communication with a deeply implanted antenna using RF can be challenging due to the significant loss of electromagnetic (EM) signal at the air–skin interface, and second, due to the propagation and reflection of EM waves from different tissue boundaries. The air–skin interface loss of the EM wave is pronounced due to the absence of a matching medium. This paper investigates the EM propagation losses in the human body and presents a choice of optimal frequency for the design of the cardiac implant antenna and the dielectric properties of the matching medium. First, the dielectric properties of all tissues present in the human thorax including skin, fat, muscle, cartilage, and heart are analyzed as a function of frequency to study the EM wave absorption at different frequencies. Second, the penetration of EM waves inside the biological tissues is analyzed as a function of frequency. Third, a transmission line (TL) formalism approach is adopted to examine the optimal frequency band for designing a cardiac implant antenna and the matching medium for the air–skin interface. Finally, experimental validation is performed at two ISM frequencies, 433 MHz and 915 MHz, selected from the optimal frequency band (0.4–1.5 GHz) suggested by our analytical investigation. For experimental validation, two off-the-shelf flexible dipole antennas operating at selected ISM frequencies were used. The numerical and experimental findings suggested that for the specific application of a cardiac implant with a penetration depth of 7–17 cm, the most effective frequency range for operation is within 0.4–1.5 GHz. The findings based on the dielectric properties of thorax tissues, the penetration depth of EM waves, and the optimal frequency band have provided valuable information on developing and optimizing CWIMDs for cardiac care applications.

show abstract

Section: Methodsmentioning

confidence: 99%

Optimizing Cardiac Wireless Implant Communication: A Feasibility Study on Selecting the Frequency and Matching Medium

Amin

Rehman

Farooq

et al. 2023

Sensors

View full text Add to dashboard Cite

show abstract

“…The integration of MEMS devices with electronic devices is also another potential area for acoustic devices where the implanted devices can be combined with wireless activation, charging, sensing, and continuous monitoring. 276,277 New trends advocate for the integration of low-cost and portable imaging systems, such as smartphones, with acoustic micro-imaging techniques to revolutionize the field of PoC sensing. 278 As an example, smartphones can be integrated to acoustofluidics platforms for point of care testing, 279 where the digital input and output of acoustic biosensors facilitate both the activation and the electronic readout.…”

Section: Future Trend and Outlookmentioning

confidence: 99%

Section: Future Trend and Outlookmentioning

confidence: 99%

Acoustofluidics – changing paradigm in tissue engineering, therapeutics development, and biosensing

2023

View full text Add to dashboard Cite

show abstract

“…In a variety of applications, including implants and other biomedical applications, there is a need for a sensor that can operate passively and wirelessly [17,18]. Zou et al [19] described a method for wirelessly querying surface acoustic wave (SAW) sensors implanted in the major pulmonary artery, where surface acoustic wave systems are used to monitor pressure. Bao et al [20] designed a strain sensor using a structure that consists of AlN/Pt/Ti/SiO2 deposited on a silicon substrate.…”

Section: Introductionmentioning

confidence: 99%

Surface Acoustic Wave (SAW) Sensors for Hip Implant: A Numerical and Computational Feasibility Investigation Using Finite Element Methods

et al. 2023

View full text Add to dashboard Cite

In this paper, a surface acoustic wave (SAW) sensor for hip implant geometry was proposed for the application of total hip replacement. A two-port SAW device was numerically investigated for implementation with an operating frequency of 872 MHz that can be used in more common radio frequency interrogator units. A finite element analysis of the device was developed for a lithium niobate (LiNBO3) substrate with a Rayleigh velocity of 3488 m/s on COMSOL Multiphysics. The Multiphysics loading and frequency results highlighted a good uniformity with numerical results. Afterwards, a hip implant geometry was developed. The SAW sensor was mounted at two locations on the implant corresponding to two regions along the shaft of the femur bone. Three discrete conditions were studied for the feasibility of the implant with upper- and lower-body loading. The loading simulations highlighted that the stresses experienced do not exceed the yield strengths. The voltage output results indicated that the SAW sensor can be implanted in the hip implant for hip implant-loosening detection applications.

show abstract

Wireless Interrogation of Implantable SAW Sensors

Cited by 19 publications

References 17 publications

Optimizing Cardiac Wireless Implant Communication: A Feasibility Study on Selecting the Frequency and Matching Medium

Optimizing Cardiac Wireless Implant Communication: A Feasibility Study on Selecting the Frequency and Matching Medium

Acoustofluidics – changing paradigm in tissue engineering, therapeutics development, and biosensing

Surface Acoustic Wave (SAW) Sensors for Hip Implant: A Numerical and Computational Feasibility Investigation Using Finite Element Methods

Contact Info

Product

Resources

About