Muhammad Solihin Zulkefli
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Preferred name
Muhammad Solihin Zulkefli
Official Name
Muhammad Solihin, Zulkefli
Alternative Name
Zulkefli, Muhammad Solihin
Zulkefli, Muhammad S.
Zulkefli, M. S.
Main Affiliation
Scopus Author ID
54783802700
Researcher ID
EIS-8616-2022

Research Output
Now showing 1 - 4 of 4
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Experimental wireless link and SAR assessments of an implantable PIFA for biotelemetry in the 2.45 GHz band

2023 , Muhammad Solihin Zulkefli , Kai Zhang , Mariella Sarestoniemi , Sami Myllymäki , William George Whittow , Sen Yan , Ping Jack Soh

An experimental wireless link and specific absorption rate (SAR) assessment is presented in this work. A compact planar inverted-F antenna (PIFA) is designed and evaluated for biotelemetry application as an antenna at 2.45 GHz band. The proposed antenna provided a satisfactory bandwidth per unit volume using a two-layered stacked structure consisting of a high-frequency laminate and a low loss ceramic layer. The antenna was first co-designed inside several different types of phantom boxes to optimize its performance, considering computational resources. Next, a semisolid intestinal phantom model used in simulations were chosen to be fabricated for experimental evaluations. Evaluation results indicated a satisfactory antenna's operation from 2.13 to 2.81 GHz (bandwidth of 27.8%), with realized gains of -26.49 dBi when implanted at 45 mm inside the phantom. Next, measurements were performed on the antenna's communication link with a wearable antenna to study the effects its depth (from 10 to 45mm), indicating transmission coefficients of between -40 and -60 dB at 2.45 GHz. Finally, its SAR levels are evaluated experimentally using a commercial measurement system when implanted within the human tissue. Results indicated satisfactory level of 0.685 W/kg (averaged over 10 g of tissues) and is suitable for biotelemetry application.

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The effects of metallic loop-like accessory worn on the human body on SAR at 2.45 GHz

2017-12-11 , Zainal H.H. , Hasliza A Rahim @ Samsuddin , Soh Ping Jack , Khairul Najmy Abdul Rani , Herwansyah Lago , Muhammad Solihin Zulkefli , Yah N.F.N.

This paper presents the Specific Absorption Rates (SAR) in the human body with a monopole antenna. The distance between the antenna and the body were varied at different distances. The parameters (ϵr, σ) used in the human body set according to the standard tissue equivalent liquids recommended by the IEEE and FCC. The simulations were made by means of CST Microwave Studio software at frequencies of 2.45GHz.The effect of the body on the SAR calculation in the body were measured. The SAR values were recorded in term of SAR for 10g of tissue. The TM is positioned against the metallic loop-like accessory, place on the left wrist of the generic arm at a varied distance from the cylindrical phantom. Numerical analysis conducted using a broadband textile monopole antenna (TM) with variations of orientation and distance showed that SAR values increased when the TM is horizontally polarized.

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Compact ingestible planar inverted-F antenna (PIFA) for biotelemetry systems

2015 , Muhammad Solihin Zulkefli

Bleeding from the gastrointestinal (GI) tract is a common medical problem. The GI tract starts at the mouth, going to the oesophagus, stomach, small intestine, colon and end at the rectum and anus. The traditional wired endoscopy made it possible to diagnose the oesophagus, stomach, colon, rectum and anus, but limited by physical reasons, leaving the remaining 20 feet of the small intestines regardless using upper or lower endoscopy procedures. An ingestible wireless biomedical device or wireless capsule endoscope fitted with a mini video camera and small enough to swallow can painlessly examine the parts that wired endoscopy cannot reach for diagnosing unexplained bleeding or other abnormalities. The challenging demand of ingestible wireless biomedical device performance reflects on the difficulties of designing the antenna for those device since the antenna plays a key role for having an abundance of quality communication links and miniaturization of the whole device, compared to the other essential components. In this thesis, a compact planar inverted-F antenna (PIFA) is proposed to be integrated with an ingestible tablet antenna system for biotelemetry application in the 2.4-2.48 GHz industrial, scientific, and medical (ISM) band. By taking the tissue properties and its losses, the design of the proposed antenna was performed inside a phantom box filled with body tissue simulating liquid (BTSL) (εr = 52.7). Besides reducing simulation time, this is mainly due to the practical ease to validate and measure its similar performance within the environment of a human small intestine (εr = 54.4). The proposed antenna is compact and is sized at 859 mm3 (15 mm x 12 mm x 4.7748 mm). It is built using twostacked structures; Taconic TLY-5 (εr = 2.2, tan δ = 0.0009) substrate and Eccostock HiK500F ceramic material (εr = 30, tan δ = 0.002). The resonance characteristic, radiation performance, specific absorption rate (SAR) distribution and communication link of the proposed antenna inside the BTSL is evaluated and compared with its performance inside a four-layer canonical tissue model (skin, fat, muscle and small intestine). Most importantly, the proposed antenna achieved the highest bandwidth per unit volume (BW/Vd) compared to other work in literature for in-body applications.

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A review of implantable and ingestible antenna for wireless capsule endoscopy system

2023 , Wei Wen Tai , Muhammad Solihin Zulkefli , Ping Jack Soh

Wireless medical devices are utilized to obtain physiological signals from the human body to an external monitoring device. The in-body antenna plays a crucial role in ensuring the transmission of physiological signals for implantable or ingestible wireless medical devices. One of the wireless medical devices that involve implantable and ingestible antennas is capsule endoscopy. The implantable one is to be implanted surgically into the human body while the ingestible one is swallowed like a multi-vitamin to perform a wide variety of diagnostic and therapeutic functions in the gastrointestinal (GI) tract. A review of both antennas and their application is presented. Besides, the design of such in-body antenna in the wireless capsule endoscopy especially in current technologies (e.g Wi-Fi, WLAN, Bluetooth, IoT) is extremely challenging and intriguing owing to it deals with the challenges related to the selection of operating frequency band, type of antenna design, and antenna miniaturization technique. Most of the antenna is facing the issue with bandwidth, transmission rate, the robustness of the communication links, size constraint, components arrangement in capsule, and others that could directly affect the patient safety and performance of capsule endoscopy in the human body. Nevertheless, the application of such implantable and ingestible antenna in wireless capsule endoscopy is incessant and rapid growth along with the evolution of technology, thus eliminating any concerns related to the aforementioned challenges and their invasive nature. In this paper, comparative reviews on the design consideration of the in-body antennas are discussed.

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