Biomedical Telemetry Research Articles

Application of Medical Implants for Public Health Monitoring and Treatment

The World Health Organisation (WHO) reports that diabetes affects roughly 180 million people worldwide and that cardiovascular illnesses account for nearly 30% of all fatalities worldwide. Applications involving radio frequency (RF) or microwave technology are crucial to medical diagnosis and illness prevention. The most recent developments in the field of implantable medical devices (IMDs), such as biomedical telemetry, allow biosignals to be monitored remotely via wireless communication technology. Providing correct information to the external monitoring station is the primary function of the health maintenance monitoring scheme. Because wireless communication lessens the invasiveness of electromagnetic (EM) medical equipment, it is extremely helpful in improving patient comfort during treatment. The first swallowable pills with sensing capabilities and the introduction of pacemakers in the early 1960s both demonstrated the significance of implantable medical devices (IMDs), which enable disease monitoring and therapy. Using IMDs with wireless connection has allowed for the monitoring of both system performance and patient status. IMDs have been widely employed in healthcare systems to gather real-time signals from biosensors or preprocessed physiological bio-signals for early disease identification, improving treatment quality and promoting healthy living.

Quad-Band 1 × 4 Linear MIMO Antenna for Millimeter-Wave, Wearable and Biomedical Telemetry Applications.

In this paper, we present the design of a millimeter-wave 1 × 4 linear MIMO array antenna that operates across multiple resonance frequency bands: 26.28-27.36 GHz, 27.94-28.62 GHz, 32.33-33.08 GHz, and 37.59-39.47 GHz, for mm-wave wearable biomedical telemetry application. The antenna is printed on a flexible substrate with dimensions of 11.0 × 44.0 mm2. Each MIMO antenna element features a modified slot-loaded triangular patch, incorporating 'cross'-shaped slots in the ground plane to improve impedance matching. The MIMO antenna demonstrates peak gains of 6.12, 8.06, 5.58, and 8.58 dBi at the four resonance frequencies, along with a total radiation efficiency exceeding 75%. The proposed antenna demonstrates excellent diversity metrics, with an ECC < 0.02, DG > 9.97 dB, and CCL below 0.31 bits/sec/Hz, indicating high performance for mm-wave applications. To verify its properties under flexible conditions, a bending analysis was conducted, showing stable S-parameter results with deformation radii of 40 mm (Rx) and 25 mm (Ry). SAR values for the MIMO antenna are calculated at 28.0/38.0 GHz. The average SAR values for 1 gm/10 gm of tissues at 28.0 GHz are found to be 0.0125/0.0079 W/Kg, whereas, at 38.0 GHz, average SAR values are 0.0189/0.0094 W/Kg, respectively. Additionally, to demonstrate the telemetry range of biomedical applications, a link budget analysis at both 28.0 GHz and 38.0 GHz frequencies indicated strong signal strength of 33.69 dB up to 70 m. The fabricated linear MIMO antenna effectively covers the mm-wave 5G spectrum and is suitable for wearable and biomedical applications due to its flexible characteristics.

A Wideband Circularly Polarized Antenna With Metasurface Plane for Biomedical Telemetry

A Wideband Circularly Polarized Antenna With Metasurface Plane for Biomedical Telemetry

Novel Design of a Bandwidth Enhanced and Frequency Reconfigurable, Wearable Antenna for Body Centric Communication

This paper proposes a novel design for a frequency reconfigurable and bandwidth-enhanced antenna for use in biomedical telemetry applications. Data pertaining to a patient’s body parameters, such as blood pressure, pulse, and temperature, are gathered using sensors and then transmitted to a remote place for monitoring. The proposed antenna is connected to a wearable transmitter, which transfers the body parameter data to a centrally located nearby control unit. The antenna operates in the 5.8 GHz band in single-band mode and in the 4.27 GHz (C band) and 5.8 GHz industrial, scientific, and medical (ISM) bands in dual-band mode. The use of ethylene-vinyl acetate foam as a substrate makes the structure waterproof and ultraviolet resistant. The basic antenna structure equipped with proximity coupling offers a front-to-back ratio (FBR) of 17.62 dB and a bandwidth of 122 MHz. With an additional upper patch and resonant slots, bandwidth enhancement of 82.85% and 11.57% improvement in the FBR are achieved, respectively. Overall, a maximum FBR of 19.66 dB and gain of 5.0 dBi are attained over the resonant frequency. The specific absorption rate is found to be 0.145 W/kg for 10 gram of tissue.

Biomedical Telemetry Antenna Innovations: Progress, Uses, and Prospects for the Future

Biomedical Telemetry Antenna Innovations: Progress, Uses, and Prospects for the Future

Single-fed broadband CPW-fed circularly polarized implantable antenna for sensing medical applications.

Biomedical telemetry relies heavily on implantable antennas. Due to this, we have designed and tested a compact, a circularly polarized, a low-profile biomedical implantable antenna that operate in the 2.45 GHz ISM band. In order to keep the antenna compact, modified co-planar waveguide (CPW) technology is used. Slotted rectangular patch with one 45-degree angle slot and truncated little patch on the left end of the ground plane generate a frequency-range antenna with circular polarization. Using a 0.25-millimeter-thick Roger Duroid-RT5880 substrate with a thickness of εr = 2.2, tanδ = 0.0009 provides flexibility. The volume of the antenna is 21 mm x 13.5 mm x 0.254 mm (0.25λg × 0.16λg × 0.003λg). The antenna covers 2.35-2.55 GHz (200 MHz) in free space and 1.63-1.17 GHz (1.17 GHz) in epidermal tissue. With skin tissue that has more bandwidth, the (x and y)-axis bends of the antenna are also simulated via the simulation. Bended antenna simulations and measurements show excellent agreement. At 2.45 GHz, the skin-like gel had -10dB impedance and 3dB axial ratio (AR) bandwidths of 47.7 and 53.8%, respectively. The ultimate result is that the SAR values are 0.78 W/kg in skin over 1 g of bulk tissue, as determined by simulations. The suggested SAR values are lower than the FCC's maximum allowable limit (FCC). This antenna is small enough to be implanted in the body, making it perfect for biomedical applications.

Metasurface-Inspired Flexible Wearable MIMO Antenna Array for Wireless Body Area Network Applications and Biomedical Telemetry Devices

This article presents a sub-6GHz ISM-band flexible wearable MIMO antenna array for wireless body area networks (WBANs) and biomedical telemetry devices. The array is based on metasurface inspired technology. The antenna array consists of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2\times 2$ </tex-math></inline-formula> matrix of triangular-shaped radiation elements that were realized on 0.8 mm thick Rogers RT/duroid 5880 substrate. Radiation characteristics of the array are enhanced by isolating the surface current interaction between the individual radiators in the array. This is achieved by inserting an electromagnetic bandgap (EBG) decoupling structure between the radiating elements. The radiating elements were transformed into a metasurface by etching sub-wavelength slots inside them. The periodic arrangement of slots acts like resonant scatterers that manipulate the electromagnetic response of the surface. Results confirm that by employing the decoupling structure and sub-wavelength slots the isolation between the radiators is significantly improved ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$&gt;34.8$ </tex-math></inline-formula> dB). Moreover, there is an improvement in the array’s fractional bandwidth, gain and the radiation efficiency. The optimized array design for operation over 5.0-6.6 GHz has an average gain and efficiency of 10 dBi and 83%, respectively. Results show that the array’s performance is not greatly affected by a certain amount of bending. In fact, the antenna maintains a gain between 8.65-10.5 dBi and the efficiency between 77-83%. The proposed MIMO antenna array is relatively compact, can be easily fabricated on one side of a dielectric material, allows easy integration with RF circuitry, is robust, and maintains its characteristics with some bending. These features make it suitable for various wearable applications and biomedical telemetry devices.

A Novel Wideband and Multi-band Implantable Antenna Design for Biomedical Telemetry

In this work, a novel multi-tracks wideband and multi-band miniaturized antenna design for implanted medical devices biomedical telemetry is proposed. This antenna entirely covers seven frequency bands which are the bands (401−406) MHz of the Medical Device Radiocommunications Service (MedRadio), the three bands (433.1−434.8), (868.0−868.6), and (902.8−928.0) MHz of the Industrial, Scientific, and Medical (ISM), and the three bands (608−614) MHz, and (1.395−1.400) and (1.427−1.432) GHz of the Wireless Medical Telemetry Service (WMTS). The antenna possesses a compact full size of (19.5 × 12.9 × 0.456) mm3. The antenna miniaturization and impedance bandwidth enhancement are achieved using two techniques: the patch slotting and insertion of open-end slots in the ground plane, respectively. Prototype of proposed antenna with multi-tracks has been fabricated and tested in free space. The comparison between the simulated and measured reflection coefficient has been done and found in good agreement with each other. Furthermore, simulations of the proposed antenna implanted in the underneath the scalp in a realistic human model shows a wideband operation from 0.19 to 0.94 GHz, and from 1.38 to 1.54 GHz corresponding to return loss (S11 ≤ −10 dB). Link budget calculation is performed to specify the range of telemetry considering both Specific Absorption Rate (SAR) restrictions and effective isotropic radiated power (EIRP) limitations. The designed implantable antenna with full ground plane presents an appropriate reflection coefficient for muscle implantation. Furthermore, the designed implanted muscle antenna may be also suitable for skin implantation.

X-Shaped Slotted Patch Biomedical Implantable Antenna for Wireless Communication Networks

Biomedical implantable antennas have a major role in biomedical telemetry applications. Therefore, a compact-size low-profile implantable antenna working in industrial, scientific, and medical (ISM) band at 915 MHz is presented. The presented antenna is a simple slotted patch fed with a coaxial probe of 50 Ω impedance. The patch consists of four slotted resonators printed on a flexible Roger Duroid RT5880 substrate ( ε r = 2.2 , tan δ = 0.0009 ) with the standard thickness of 0.254 mm. The complete volume of the designed antenna is 7 mm × 7 mm × 0.254 mm ( 0.08 λ g × 0.08 λ g × 0.003 λ g ). The antenna covers the bandwidth from 800 MHz to 1 GHz (200 MHz) inside skin tissue. A good agreement between the simulation and measurements of the antenna has been obtained. Finally, the specific absorption rate (SAR) values have also been analyzed through simulations as 8.17 W/kg inside skin over 1 g of mass tissue. The proposed SAR values are less than the limit of the Federal Communications Commission (FCC). This antenna is miniaturized and an ideal applicant for applications in biomedical implants.

A Soft Surface Based Low Profile Wearable Antenna for Biomedical Telemetry

A soft surface based low profile wearable antenna operating on 5.8 GHz Industrial, Scientific and Medical (ISM) band (5.725-5.875 GHz) is presented for high speed biomedical telemetry. The flexible substrate of Ethylene-Vinyl Acetate (EVA) foam makes the structure water proof, ultra-violet resistant and mechanically stable. First, the basic antenna structure (reference) with inset feeding is designed. Initially, the forward to back power ratio obtained is 14.1 for basic design. The back radiation is further reduced by introducing soft surface around the patch. Use of two different materials as soft surface has been studied and analyzed. The maximum gain of 5.2 dBi and Front to Back Ratio (FTBR) of 25.63 is achieved for the chosen resonant frequency. The absorption of electromagnetic field by the body is reduced by 9.35 % and gain is improved by 23.68/24.40 % with reference to our basic design of antenna without soft surface. The value of Specific Absorption Rate (SAR) is 1.26 W/kg for 10 gm of human body tissue which is within the specified limits. The software simulated and experimented results are presented.

Multiband antenna design based on Gosper fractal for implantable biomedical devices

AbstractIn this paper, a novel multiband implantable planar inverted-F antenna (PIFA) antenna based on Gosper curve fractal geometry is designed for biomedical telemetry applications. The antenna has covered four dedicated frequency bands; medical implant communication system band (MICS 402–405 MHz), industrial, scientific, and medical bands (ISM 902–928 MHz and 2.4–2.5 GHz), and wireless medical telemetry services (WMTS 1395–1400 and 1429–1432 MHz). The proposed antenna is designed on Rogers RO 3010 substrate of thickness 25 mil and volume equal to 153.67 mm3. The reflection coefficient and the radiation pattern are measured inside muscle-mimicking liquid tissue phantom. The antenna has achieved the impedance bandwidth of 126, 406, 168, and 175 MHz at MICS (403 MHz), ISM (915 MHz), WMTS (1400 MHz), and ISM (2.45 GHz) with maximum gain value −33.6, −21.04, −15.48, and −10.25 dBi, respectively. The data link range between the implantable antenna and off body antenna has been performed with −16 dBm input power. Additionally, the obtained specific absorption rate with the input of 25 μW power has also been obtained within the safety limit and hence ensures the reliability of the proposed antenna.

Changes in the activity of selected muscles during deep squat correction

Background: Deep squatting, as part of postural ontogenesis, is an integral part of every athlete's training. Squats performed with the correct kinesiological pattern can ensure optimal loading of the musculoskeletal system, affect the function of the diaphragm and thus breathing in addition to positively affect the pelvic floor muscles. On the contrary, in the case of insufficient coordination, we can detect a failure in thestabilization of individual segments.Aim: The aim of the study was to find out the difference in the quality of muscle involvement in two variants of squats. The first squat was natural for an athlete without the intervention of a therapist, and in the second one we tried to adjust theindividual segments biomechanically correctly. Methods: The group included 20 athletes, with an average age of 21.85 years. The measurement took place in the MSC Dukla Banská Bystrica building at a uniform time from 10:00AM to 12:30PM. We used a biomedical telemetry system with surface EMG. M. biceps femoris, m. semitendinosus, m. vastus medialis and m. erector spinae were measured.Results: The activity of the muscles on the back of the thigh showed lower average values after squat correction by physiotherapist instructions (significant in one case). Differences in activity of all muscles: m. biceps femoris dx (p = 0.16005), sin (p = 0,00268), m. semitendinosus dx (p = 0.838), sin (p = 0.0852). m. vastus medialis dx (p= 0.35), sin (p = 0.0066), m erector spinalis dx (p = 0.118), sin (p = 0.0632).Conclusion: Our measurements showed that the correction of individual segments to the correct biomechanical position was statistically confirmed in two cases (vastus medialis sin. and m. biceps femoris sin.), But from a practical point of view we recorded a positive effect on average muscle activity. and overall squat execution efficiency.DOI: https://doi.org/10.24040/sjss.2021.7.1.37-47

Implantable Antennas for Bio-Medical Applications

Biomedical telemetry has gained a lot of attention with the development in the healthcare industry. This technology has made it feasible to monitor the physiological signs of patient remotely without traditional hospital appointments and follow up routine check-ups. Implantable Medical Devices (IMDs) play an important role to monitor the patients through wireless telemetry. IMDs consist of nodes and implantable sensors in which antenna is a major component. The implantable sensors suffer a lot of limitations. Various factors need to be considered for the implantable sensors such as miniaturization, patient safety, bio-compatibility, low power consumption, lower frequency band of operation and dual-band operation to have a robust and continuous operation. The selection of the antenna is a challenging task in implantable sensor design as it dictates performance of the whole implant. In this paper a critical review on implantable antennas for biomedical applications is presented.

A multiband antenna for biomedical telemetry and treatments

This paper presents the design of a tri-band adhesive antenna for biomedical telemetry. Since human body is lossy in nature, the signal transmitted from an implantable medical device is usually very weak. The adhesive antenna acts like a repeater which increases the strength of the signal. This allows the signal to be sent effectively to the base station. The antenna is designed to resonate at 375 MHz, 2.525 GHz and 5.625 GHz. The measurement results show that the antenna has 10 dB impedance bandwidths of 400 MHz (175 – 575 MHz), 950 MHz (2.125 – 3.075 GHz) and 1.5 GHz (5.125 – 6.625 GHz) to cover the MICS, ISM and IEEE 802.11 WLAN bands, respectively. The proposed antenna is printed on a flexible Rogers RT/duroid 5880 epoxy substrate with a volume of 70 mm × 80 mm × 1 mm. The simulated and measured performance of the antenna confirms its omnidirectional radiation patterns and dual-band operation with high return losses.

Wideband Wearable Antenna for Biomedical Telemetry Applications

This paper presents a wideband, low-profile and semi-flexible antenna for wearable biomedical telemetry applications. The antenna is designed on a semi-flexible material of RT/duroid 5880 (E <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">r</sub> = 2.2, tanδ = 0.0004) with an overall dimensions of 17 mm × 25 mm × 0.787 mm (0.2λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> × 0.29λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> × 0.009λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> ). A conventional rectangular patch is modified by adding rectangular slots to lower the resonant frequency, and the partial ground plane is modified to enhance the operational bandwidth. The final antenna model operates at 2.4 GHz with a 10-dB bandwidth (fractional bandwidth) of 1380 MHz (59.7 % at the centre frequency of 2.4 GHz). The proposed antenna maintains high gain (2.50 dBi at 2.4 GHz) and efficiency (93 % at 2.4 GHz). It is proved from the simulations and experimental results that the antenna has negligible effects in terms of reflection coefficient, bandwidth, gain, and efficiency when it is bent. Moreover, the antenna is simulated and experimentally tested in proximity of the human body, which shows good performance. The proposed wideband antenna is a promising candidate for compact wearable biomedical devices.

Novel coated differentially fed dual‐band fractal antenna for implantable medical devices

A novel differentially fed fractal antenna coated with a layer of a dielectric film and operating at two bands of Medical Implant Communication Services 402–405 MHz and Industrial, Scientific, and Medical 2.4–2.48 GHz, is investigated to enable sufficient data transmission rates, while featuring a ‘mode-control’ signal to prolong the battery life. The symmetrical fractal technology of Hilbert curve is employed to miniaturise the dimension. To facilitate interfacing with peripheral integrated circuits, differentially feeding is adopted. To demonstrate how common-mode noises are suppressed, for the first time, a detailed analysis about the noise suppression of the differential configuration with two feedings is presented. A layer of thin film is coated around the proposed antenna to isolate the effect of human tissues and alleviate the electromagnetic coupling with human body. Moreover, to draw a design methodological guideline, the key geometrical parameters are analysed numerically and theoretically. Health safety considerations, radiation performance, and link budgets are also discussed to validate the proposed antenna's applicability in biomedical telemetry.

Bio-Matched Horn: A Novel 1–9 GHz On-Body Antenna for Low-Loss Biomedical Telemetry With Implants

We present the Bio-Matched Horn antenna: a novel 1.773 cm3 on-body antenna for very low-loss communication with wireless implants across the 1–9 GHz bandwidth. To achieve this unique performance, the Bio-Matched Horn is composed of water-filled holes used to mimic the frequency-dependent permittivity of the underlying tissue over its entire bandwidth. The horn shape further allows the proposed antenna to communicate efficiently through the biological tissue for both subcutaneous and deep-tissue wireless implants. Measurement results at 2.4 GHz are in good agreement with simulations and show a transmission loss of 8.01 dB to a 4 mm-deep implant and 19.21 dB to a 2 cm-deep implant. Compared to the previous designs, this is a remarkable improvement by 14.5 and 10.8 dB for subcutaneous and deep-tissue communication, respectively. In this paper, we discuss the operation principle and design of the Bio-Matched Horn, its performance for subcutaneous and deep-tissue implant telemetry, sensitivity to rotational and positional misalignments, and specific absorption rate performance.

A Miniaturized Four-Element MIMO Antenna With EBG for Implantable Medical Devices

A miniaturized four-element multiple-input-multiple-output (MIMO) antenna operating in the band of Industrial, Scientific, and Medical (ISM) 2.4–2.48 GHz is investigated to supply sufficient transmission rate and fight against multipath fading. A single antenna integrates with dual radiators, and each radiator is owned by a pair of subantenna units, greatly diminishing the whole dimensions of the implanted MIMO device. A cross-shaped slot etched in the radiator, a branch extending on the conductor ground, and a pair of electromagnetic band gaps are integrated to achieve high isolation. The proposed MIMO antenna has the compact dimensions of 18.5 mm × 18.5 mm × 1.27 mm. The simulation in the three-layer phantom indicates that the impedance matching is good with a bandwidth of 18.64% (2.14–2.58 GHz) and a maximum gain of –15.18 dBi and the mutual coupling is reduced to less than –15.99 dB at the ISM band. An <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ex-vivo</i> test was implemented in a fresh pork slab, and the measurement results are well matched with the simulation ones. Health safety considerations and link budget are discussed to validate the antenna's availability in biomedical telemetry, and the envelope correlation coefficient is computed, illustrating the high independence between antenna elements.

Design and simulation‐based performance evaluation of a miniaturised implantable antenna for biomedical applications

Biomedical telemetry is an emerging field of research which enables the formation of a transmission link from inside a living body to an external device. Implantable medical devices are now one of such valuable advancement in the field of biomedical telemetry. Implantable patch antennas are gaining attention and are becoming more of a choice for implantable medical devices that uses mostly RF telemetry. In this work, a state-of-the-art design for a rectangular implantable flexible patch antenna is proposed. The operation band for the antenna is chosen in the Industrial, Scientific and Medical (ISM) band (2.4-2.4835 GHz). The tiny dimension of the antenna, including the 9.45 μm thickness of the patch itself allows the antenna to be highly flexible and provides excellent results even at extreme bent conditions. For simulation environment, a three-layer human tissue model was used, where the antenna was encapsulated between the fat and skin layer. CST Microwave Studio was chosen to design and simulate the antenna. Several performance parameters were simulated, such as the operating resonant frequency, the return loss, radiation pattern, specific absorption rate and also sensitivity of the antenna when introduced to bending.

Design of antenna in Wireless Body Area Network (WBAN) for biotelemetry applications

Biomedical telemetry system transmits biological signal to a long distance. Antenna finds vital role in transmitting a biological signals. Patch Antennas are integrated with medical devices and used widely because of their design flexibility and shape . This paper proposes two antennas for telemetry application. Yagi antennas provide high directivity. Patch antennas are of light weight and is easy to carry. It can be fabricated on the fabric easily. Hence it proves to be an ideal solution for biotelemetry where the patients can wear the antenna, which in turn can collect the bio signals from the body and send it to the monitoring station. This combination of yagi and patch antennas gives sufficient gain and directivity his paper proposes the design of two Yagi Patch Antennas (YPA) with two different substrates for telemetry purpose. A miniature telemetry antenna model is designed, which captures information from the human body and transmits it to the monitoring station. The biological information is transmitted at a frequency of 2.45 GHz. in WLAN range. The performance of the antenna is simulated and analyzed using FEKO software.