Biopotential Measurements Research Articles

The evaluation of a novel single-lead biopotential device for home sleep testing.

This paper reports on the clinical evaluation of the sleep staging performance of a novel single-lead biopotential device. 133 patients suspected of obstructive sleep apnea were included in a multi-site cohort. All patients underwent polysomnography and received the study device, a single-lead biopotential measurement device attached to the forehead. Clinical endpoint parameters were selected to evaluate the device's ability to determine sleep stages. Finally, the device's performance was compared to the clinical study results of comparable devices. Concurrent PSG and study device data were successfully acquired for 106 of the 133 included patients. The results of this study demonstrated significant similarity in overall sleep staging performance (5-stage Cohen's Kappa of 0.70) to the best-performing reduced-lead biopotential device to which it was compared (5-stage Cohen's Kappa of 0.73). Contrary to the comparator devices, the study device reported a higher Cohen's Kappa for REM (0.78) compared to N3 (0.61), which can be explained by its particular measuring electrode placement (diagonally across the lateral cross-section of the eye). This placement was optimized to ensure the polarity of rapid eye movements could be adequately captured, enhancing the capacity to discriminate between N3 and REM sleep when using only a single-lead setup. The results of this study demonstrate the feasibility of incorporating a single-lead biopotential extension in a reduced-channel home sleep apnea testing setup. Such incorporation could narrow the gap in the functionality of reduced-channel home sleep testing and in-lab polysomnography without compromising the patient's ease of use and comfort.

Self-Healing and Shear-Stiffening Electrodes for Wearable Biopotential Sensing and Gesture Recognition.

The achievement of flexible skin electrodes for dynamic monitoring of biopotential is one of the challenging issues in flexible electronics due to the interference of large acceleration and heavy sweat that influence the stability of skin-electrode interfaces. This work presents materials and techniques to achieve self-healing and shear-stiffening electrodes and an associated flexible system that can be used for multichannel biopotential measurement on the skin. The electrode that is based on a composite of silver (Ag) flakes, Ag nanowires, and polyborosiloxane offers an electrical conductivity of 9.71 × 104 S/m and a rheological characteristic that ensures stable and fully conformal contact with skin and easy removal under different shear rates. The electrode can maintain its conductivity even after being stretched by more than 60% and becomes self-healed after mechanical damage. The combination of the electrodes with a screen-printed multichannel flexible sensor allows stable monitoring of both static and dynamic electromyography signals, leading to the acquisition of high-quality multilead biopotential signals that can be readily extracted to yield gesture recognition results with over 97.42% accuracy. The conductive self-healing materials and flexible sensors may be utilized in various daily biopotential sensing applications, allowing highly stable dynamic measurement to facilitate artificial intelligence-enabled health condition diagnosis and human-computer interface.

Remotely Powered Two-Wire Cooperative Sensors for Bioimpedance Imaging Wearables.

Bioimpedance imaging aims to generate a 3D map of the resistivity and permittivity of biological tissue from multiple impedance channels measured with electrodes applied to the skin. When the electrodes are distributed around the body (for example, by delineating a cross section of the chest or a limb), bioimpedance imaging is called electrical impedance tomography (EIT) and results in functional 2D images. Conventional EIT systems rely on individually cabling each electrode to master electronics in a star configuration. This approach works well for rack-mounted equipment; however, the bulkiness of the cabling is unsuitable for a wearable system. Previously presented cooperative sensors solve this cabling problem using active (dry) electrodes connected via a two-wire parallel bus. The bus can be implemented with two unshielded wires or even two conductive textile layers, thus replacing the cumbersome wiring of the conventional star arrangement. Prior research demonstrated cooperative sensors for measuring bioimpedances, successfully realizing a measurement reference signal, sensor synchronization, and data transfer though still relying on individual batteries to power the sensors. Subsequent research using cooperative sensors for biopotential measurements proposed a method to remove batteries from the sensors and have the central unit supply power over the two-wire bus. Building from our previous research, this paper presents the application of this method to the measurement of bioimpedances. Two different approaches are discussed, one using discrete, commercially available components, and the other with an application-specific integrated circuit (ASIC). The initial experimental results reveal that both approaches are feasible, but the ASIC approach offers advantages for medical safety, as well as lower power consumption and a smaller size.

A High-Performance, Secure Custom Electronics Circuit for Biopotential Measurement and Processing

Purpose: In this paper, we propose a secure wearable and portable device aiming to (i) monitor physical activity in medical and clinical rehabilitation, (ii) evaluate the subject's movements in sports environments, and (iii) monitor wellness indicators. Materials and Methods: The innovative low-power custom circuit can acquire, pre-process, digitalize, and transmit EMG signals to a Raspberry PI4 device via a low-energy Bluetooth module. The Raspberry PI4 is a hub that sends data to a cloud-based system for remote monitoring and processing. The best cybersecurity practices have been implemented: firewall, anti-DDoS and SELinux. Results: We have assessed the system's vulnerability before and after the system's hardening. SELinux makes the system safer and prevents unauthorized access to patients' data health by tampering with the devices. Conclusion: Adopting IoT systems in telemedicine requires greater attention to cybersecurity. It is necessary to implement security mechanisms to guarantee the privacy of patient's health data.

Soft electrodes for simultaneous bio-potential and bio-impedance study of the face

The human body’s vascular system is a finely regulated network: blood vessels can change in shape (i.e. constrict, or dilate), their elastic response may shift and they may undergo temporary and partial blockages due to pressure applied by skeletal muscles in their immediate vicinity. Simultaneous measurement of muscle activation and the corresponding changes in vessel diameter, in particular at anatomical regions such as the face, is challenging, and how muscle activation constricts blood vessels has been experimentally largely overlooked. Here we report on a new electronic skin technology for facial investigations to address this challenge. The technology consists of screen-printed dry carbon electrodes on soft polyurethane substrate. Two dry electrode arrays were placed on the face: One array for bio-potential measurements to capture muscle activity and a second array for bio-impedance. For the bio-potential signals, independent component analysis (ICA) was used to differentiate different muscle activations. Four-contact bio-impedance measurements were used to extract changes (related to artery volume change), as well as beats per minute (BPM). We performed concurrent bio-potential and bio-impedance measurements in the face. From the simultaneous measurements we successfully captured fluctuations in the superficial temporal artery diameter in response to facial muscle activity, which ultimately changes blood flow. The observed changes in the face, following muscle activation, were consistent with measurements in the forearm and were found to be notably more intricate. Both at the arm and the face, a clear increase in the baseline impedance was recorded during muscle activation (artery narrowing), while the impedance changes signifying the pulse had a clear repetitive trend only at the forearm. These results reveal the direct connection between muscle activation and the blood vessels in their vicinity and start to unveil the complex mechanisms through which facial muscles might modulate blood flow and possibly affect human physiology.

GAPses: Versatile smart glasses for comfortable and fully-dry acquisition and parallel ultra-low-power processing of EEG and EOG.

Recent advancements in head-mounted wearable technology are revolutionizing the field of biopotential measurement, but the integration of these technologies into practical, user-friendly devices remains challenging due to issues with design intrusiveness, comfort, reliability, and data privacy. To address these challenges, this paper presents GAPSES, a novel smart glasses platform designed for unobtrusive, comfortable, and secure acquisition and processing of electroencephalography (EEG) and electrooculography (EOG) signals.We introduce a direct electrode-electronics interface within a sleek frame design, with custom fully dry soft electrodes to enhance comfort for long wear. The fully assembled glasses, including electronics, weigh 40 g and have a compact size of 160 mm × 145 mm. An integrated parallel ultra-low-power RISC-V processor (GAP9, Greenwaves Technologies) processes data at the edge, thereby eliminating the need for continuous data streaming through a wireless link, enhancing privacy, and increasing system reliability in adverse channel conditions. We demonstrate the broad applicability of the designed prototype through validation in a number of EEG-based interaction tasks, including alpha waves, steady-state visual evoked potential analysis, and motor movement classification. Furthermore, we demonstrate an EEG-based biometric subject recognition task, where we reach a sensitivity and specificity of 98.87% and 99.86% respectively, with only 8 EEG channels and an energy consumption per inference on the edge as low as 121 μJ. Moreover, in an EOG-based eye movement classification task, we reach an accuracy of 96.68% on 11 classes, resulting in an information transfer rate of 94.78 bit/min, which can be further increased to 161.43 bit/min by reducing the accuracy to 81.43%. The deployed implementation has an energy consumption of 40 μJ per inference and a total system power of only 12.4 mW, of which only 1.61% is used for classification, allowing for continuous operation of more than 22 h with a small 75 mAh battery.

Development of Flexible Medical Electrodes Using Carrageenan-Based Bioplastics with the Addition of Conductive Hybrid Materials Graphite and Silver Nanoparticles.

Electrodes are crucial in medical devices, specifically health monitoring devices for biopotential measurements such as electrocardiography, electromyography (EMG), and electroencephalography. The commonly used rigid electrodes have limitations in their skin-electrode contact quality since they cannot conform to the skin's surface area and body contours. Flexible electrodes have been developed to better conform to the body's surface contours, improving ion transfer and minimizing motion artifacts, thereby enhancing the signal-to-noise ratio (SNR). Bioplastic substrates based on carrageenan have been chosen for their safety, abundance, flexibility, and ease of customization. Hybrid materials of graphite and silver nanoparticles (graphite-AgNPs) exhibit high electron capacitance, low charge transfer resistance, and superior surface catalytic activity. These make them ideal as conductive fillers for bioplastics to achieve good electrical characteristics as electrodes. The effect of the graphite-AgNP filler concentration, graphite particle size, and flexible electrode thickness was evaluated to assess their impact on the electrical and mechanical properties of the fabricated flexible electrodes. The graphite-AgNP fillers were incorporated into a bioplastic matrix, resulting in flexible electrodes with improved conductivity with increasing percentages of graphite-AgNP at the expense of flexibility. The thickness of the flexible electrode was varied to evaluate its effect on the conductivity. A graphite size reduction was performed to improve the electrical properties while maintaining the mechanical properties. The most optimal variation of flexible electrodes with desirable electrical and mechanical properties was achieved by adding 25% graphite-AgNP to the carrageenan, using graphite particles of 400-700 nm, and using the thinnest electrode. The optimized electrode also exhibited an improved SNR value in EMG signal measurements compared to conventional Ag/AgCl electrodes. This research presents a novel approach to developing environmentally friendly, customizable, and flexible electrodes for medical applications.

Surface electromyography using dry polymeric electrodes.

Conventional wet Ag/AgCl electrodes are widely used in electrocardiography, electromyography (EMG), and electroencephalography (EEG) and are considered the gold standard for biopotential measurements. However, these electrodes require substantial skin preparation, are single use, and cannot be used for continuous monitoring (>24 h). For these reasons, dry electrodes are preferable during surface electromyography (sEMG) due to their convenience, durability, and longevity. Dry conductive elastomers (CEs) combine conductivity, flexibility, and stretchability. In this study, CEs combining poly(3,4-ehtylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS) in polyurethane are explored as dry, skin contacting EMG electrodes. This study compares these CE electrodes to commercial wet Ag/AgCl electrodes in five subjects, classifying four movements: open hand, fist, wrist extension, and wrist flexion. Classification accuracy is tested using a backpropagation artificial neural network. The control Ag/AgCl electrodes have a 98.7% classification accuracy, while the dry conductive elastomer electrodes have a classification accuracy of 99.5%. As a conclusion, PEDOT based dry CEs were shown to successfully function as on-skin electrodes for EMG recording, matching the performance of Ag/AgCl electrodes, while addressing the need for minimal skin prep, no gel, and wearable technology.

Gas-permeable and stretchable on-skin electronics based on a gradient porous elastomer and self-assembled silver nanowires

On-skin electronics offers a noninvasive method for continuous and stable signal monitoring, which has played a significant role in healthcare and rehabilitation engineering. However, most present on-skin electronicses are highly restricted by their gas permeability and stretchability due to the materials, fabrication process, and cost. This study develops gas-permeable and stretchable on-skin electronics fabricated via a gradient porous elastomer and self-assembled silver nanowires. The introduction of a gradient porous structure offers the elastomer substrate a good water vapor permeability of 3073.3 g day−1 m−2, which is much higher than the average evaporation rate of water vapor on human skin (432 g day−1m−2). Additionally, the examined electronic device has no adverse effects on the skin and possesses good stretchability and flexibility (110%, 0.07778 MPa). In addition, it offers excellent fatigue resistance (0.70% electrical resistance change within 1000 stretch cycles). The electronic device achieves conformal and comfortable contact with human skin for a long period of wearing and accomplishes high-quality biopotential measurement with a high signal-to-noise ratio (SNR) during electromyography (EMG) signal detection. The proposed simple fabrication process may supply inspiration for new on-skin electronics used in biological signal detection and rehabilitation engineering.

Comparison and Integration of Voltage and Charge Amplifiers for Capacitive ECG Measurements.

Sensing with capacitive electrodes is of interest for long-term, comfortable bio-potential measurements (e.g., ECG). However, due to the small body-to-electrode capacitance (Ce), the design of the associated front-end amplifier remains a challenge. Both voltage amplifiers (VA) and charge amplifiers (CA) can be employed. While basic comparisons of both typologies were done before, this paper extends the comparison to their responses to artifacts (caused by motion or interference). Further, a VA-CA-switchable amplifier is proposed, allowing to adapt the amplifier type to different situations, and enabling to estimate the body-to-electrode capacitance Ce in a passive way. A VA-CA switchable amplifier was implemented in a 180 nm CMOS process. The responses to artifacts for VA and CA were studied by modelling, simulations and experiments using the custom IC. The proposed Ce estimation method was validated by electrical tests and in-vivo tests. VAs are less affected by Ce variation artifacts, while CAs recover faster from triboelectricity artifacts. In a VA, these two artifacts are multiplicative and get modulated if they occur simultaneously, but in a CA they remain independent. The combined VA-CA amplifier has the potential for optimal amplifier selection according to the properties of the recorded signal, the value of Ce and the actual presence of artifacts. Moreover, it can estimate Ce without extra hardware. The proposed VA-CA switchable structure is superior to an individual VA or CA, thanks its adaptability to signal quality and artifacts, and it provides extra information on the body-to-electrode interface quality (Ce).

Implementation of a New Versatile Bio-Potential Measurement System

In this paper, a novel system for measuring bio-potentials, including electroencephalography (EEG), electrocardiography (ECG) and electromyography (EMG) signals, was implemented. This system is based on the high-precision (24-bit) analog front-end ADS1299 with eight input channels. The aim of this work is to provide a low-cost platform for researchers in neuroscience, brain–computer interfaces, ECG pattern recognition and myoelectric control for Robotic Hand-Assisted Training, etc. Compared to the existing systems, this design uses a module called ESP-WROOM-32 based on a 32-bit dual-core Xtensa LX6 microprocessor in which all control and communication functions have been integrated into a single package, giving the possibility to interface the system with the Raspberry Pi via the USB interface or via the wireless interface (Wi-Fi and Bluetooth). The paper presents a detailed study of the system in terms of hardware and software implementation. In addition, an experimental process has been conducted with the aim of evaluating the proposed prototype. With a common mode rejection ratio higher than 110[Formula: see text]dB and an input referred noise less than 2[Formula: see text][Formula: see text]V (peak-to-peak) as well as the good quality of the measured biopotentials during all the proposed scenarios, the model can be qualified to be functioning properly following the recommendations of the ADS1299 manufacturer. Finally, a conclusion is made to summarize the results achieved while highlighting the future study and the suggestions for improving the presented design.

Stretchable electrodes for biopotential measurements in wearable patches

Abstract Soft, stretchable, and flexible electrodes offer a unique and nonintrusive option to monitor essential biopotential signals from the skin, which can be related to the functioning and status of different organs including the heart. Such stretchable electrodes, by forming an intimate contact to the human skin, not only increase the signal-to-noise ratio of the recorded biopotentials and reduce eventual signal artifacts, but are also more pleasant to wear. We developed a stretchable electrode patch for electrocardiogram (ECG) monitoring utilizing the medical-grade, transparent, and stretchable material Styrene-ethylene-butylene-styrene (SEBS). Our fabrication process is compatible with standard micro- and nano clean room processes and could be up-scaled accordingly.

Upcycling Compact Discs for Flexible and Stretchable Bioelectronic Applications

Electronic waste is a global issue brought about by the short lifespan of electronics. Viable methods to relieve the inundated disposal system by repurposing the enormous amount of electronic waste remain elusive. Inspired by the need for sustainable solutions, this study resulted in a multifaceted approach to upcycling compact discs. The once-ubiquitous plates can be transformed into stretchable and flexible biosensors. Our experiments and advanced prototypes show that effective, innovative biosensors can be developed at a low-cost. An affordable craft-based mechanical cutter allows pre-determined patterns to be scored on the recycled metal, an essential first step for producing stretchable, wearable electronics. The active metal harvested from the compact discs was inert, cytocompatible, and capable of vital biopotential measurements. Additional studies examined the material’s resistive emittance, temperature sensing, real-time metabolite monitoring performance, and moisture-triggered transience. This sustainable approach for upcycling electronic waste provides an advantageous research-based waste stream that does not require cutting-edge microfabrication facilities, expensive materials, and high-caliber engineering skills.

Size Constraint to Limit Interference in DRL-Free Single-Ended Biopotential Measurements

In this work, it is shown that small, battery-powered wireless devices are so robust against electromagnetic interference that single-ended amplifiers can become a viable alternative for biopotential measurements, even without a Driven Right Leg (DRL) circuit. A power line interference analysis is presented for this case showing that this simple circuitry solution is feasible, and presenting the constraints under which it is so: small-size devices with dimensions less than 40 mm × 20 mm. A functional prototype of a two-electrode wireless acquisition system was implemented using a single-ended amplifier. This allowed validating the power-line interference model with experimental results, including the acquisition of electromyographic (EMG) signals. The prototype, built with a size fulfilling the proposed guidelines, presented power-line interference voltages below 1.2 µVPP when working in an office environment. It can be concluded that a single-ended biopotential amplifier can be used if a sufficiently large isolation impedance is achieved with small-size wireless devices. This approach allows measurements with only two electrodes, a very simple front-end design, and a reduced number of components.

Dimensionality Reduction and Prediction of Impedance Data of Biointerface.

Electrochemical impedance spectroscopy (EIS) is the golden tool for many emerging biomedical applications that describes the behavior, stability, and long-term durability of physical interfaces in a specific range of frequency. Impedance measurements of any biointerface during in vivo and clinical applications could be used for assessing long-term biopotential measurements and diagnostic purposes. In this paper, a novel approach to predicting impedance behavior is presented and consists of a dimensional reduction procedure by converting EIS data over many days of an experiment into a one-dimensional sequence of values using a novel formula called day factor (DF) and then using a long short-term memory (LSTM) network to predict the future behavior of the DF. Three neural interfaces of different material compositions with long-term in vitro aging tests were used to validate the proposed approach. The results showed good accuracy in predicting the quantitative change in the impedance behavior (i.e., higher than 75%), in addition to good prediction of the similarity between the actual and the predicted DF signals, which expresses the impedance fluctuations among soaking days. The DF approach showed a lower computational time and algorithmic complexity compared with principal component analysis (PCA) and provided the ability to involve or emphasize several important frequencies or impedance range in a more flexible way.

Highly Stretchable and Self-Adhesive Elastomers Based on Polymer Chain Rearrangement for High-Performance Strain Sensors.

Polydimethylsiloxane (PDMS) has been widely used in many fields. However, the polymerization process of the siloxane chain is highly complex, and it is challenging to enhance the mechanical properties of PDMS elastomers significantly. We found that adding a small amount of polyoxyethylene lauryl ether (Brij-35) into siloxane polymers can result in B-PDMS elastomers with high tensile properties and strong adhesion. It is worth noting that this is the first study to improve the mechanical properties of PDMS using Brij-35. Here, we intensely studied a variety of process conditions that influence the cross-linking of PDMS, emphasizing the modification mechanism of the polymer chain. The hydroxyl groups in Brij-35 and the platinum catalyst in PDMS form a complex, which inhibits the cross-linking process of PDMS, not only forming a heterogeneous cross-linking network in the B-PDMS but also disentangling the strongly wound siloxane polymer chain, thereby rearranging the PDMS polymer chains. Furthermore, in order to prepare a strain sensor based on the B-PDMS elastomer under safe and convenient conditions, we prepared laser-scribed graphene powder (LSGP) by laser-scribing of graphene oxide (GO) films, and the LSGP and carbon nanotubes (CNTs) endowed the B-PDMS elastomers with excellent electrical properties. The sensor could firmly adhere to the skin and generate a high-quality response to a variety of human motions, and it could drive the robotic hand to grasp and lift objects accurately. The high-performance strain sensors based on B-PDMS have broad applications in medical sensing and biopotential measurement.

All-Nanofiber-Based Janus Epidermal Electrode with Directional Sweat Permeability for Artifact-Free Biopotential Monitoring.

Epidermal electronics have been developed with gas/sweat permeability for long-term wearable electrophysiological monitoring. However, the state-of-the-art breathable epidermal electronics ignore the sweat accumulation and immersion at the skin/device interface, resulting in serious degradation of the interfacial conformality and adhesion, leading to signal artifacts with unstable and inaccurate biopotential measurements. Here, the authors present an all-nanofiber-based Janus epidermal electrode endowed with directional sweat transport properties for artifact-free biopotential monitoring. The designed Janus multilayered membrane (≈15µm) of superhydrophilic-hydrolyzed-polyacrylonitrile (HPAN)/polyurethane (PU)/Ag nanowire (AgNW) can quickly (less than 5 s) drive sweat away from the skin/electrode interface while resisting its penetration in the reverse direction. Along with the medical adhesive (MA)-reinforced junction-nodes, the adhesion strength among the heterogeneous interfaces can be greatly enhanced for robust mechanical-electrical stability. Therefore, their measured on-body electromyography (EMG) and electrocardiography (ECG) signals are free of sweat artifacts with negligible degradation and baseline drift compared to commercial Ag/AgCl gel electrodes and hydrophilic textile electrodes. This work paves a way to design novel directional-sweat-permeable epidermal electronics that can be conformally attached under sweaty conditions for long-term biopotential monitoring and shows the potential to apply epidermal electronics to many challenging conditions.

A novel high-purity carbon-nanotube yarn electrode used to obtain biopotential measurements in small animals: flexible, wearable, less invasive, and gel-free operation

A novel high-purity carbon-nanotube yarn electrode used to obtain biopotential measurements in small animals: flexible, wearable, less invasive, and gel-free operation

Me-Doped Ti-Me Intermetallic Thin Films Used for Dry Biopotential Electrodes: A Comparative Case Study.

In a new era for digital health, dry electrodes for biopotential measurement enable the monitoring of essential vital functions outside of specialized healthcare centers. In this paper, a new type of nanostructured titanium-based thin film is proposed, revealing improved biopotential sensing performance and overcoming several of the limitations of conventional gel-based electrodes such as reusability, durability, biocompatibility, and comfort. The thin films were deposited on stainless steel (SS) discs and polyurethane (PU) substrates to be used as dry electrodes, for non-invasive monitoring of body surface biopotentials. Four different Ti–Me (Me = Al, Cu, Ag, or Au) metallic binary systems were prepared by magnetron sputtering. The morphology of the resulting Ti–Me systems was found to be dependent on the chemical composition of the films, specifically on the type and amount of Me. The existence of crystalline intermetallic phases or glassy amorphous structures also revealed a strong influence on the morphological features developed by the different systems. The electrodes were tested in an in-vivo study on 20 volunteers during sports activity, allowing study of the application-specific characteristics of the dry electrodes, based on Ti–Me intermetallic thin films, and evaluation of the impact of the electrode–skin impedance on biopotential sensing. The electrode–skin impedance results support the reusability and the high degree of reliability of the Ti–Me dry electrodes. The Ti–Al films revealed the least performance as biopotential electrodes, while the Ti–Au system provided excellent results very close to the Ag/AgCl reference electrodes.

Novel 3D-printed Electrodes for Implantable Biopotential Monitoring.

A major bottleneck in the manufacturing process of a medical implant capable of biopotential measurements is the design and assembly of a conductive electrode interface. This paper presents the use of a novel 3D-printing process to integrate conductive metal surfaces on a low-temperature co-fired ceramic base to be deployed as electrodes for electrocardiography (ECG) implants for small animals. In order to fit the ECG sensing system within the size of an injectable microchip implant, the electronics along with a pin-type lithium-ion battery are inserted into a cylindrical glass tube with both ends sealed by these 3D printed composite electrode discs using biomedical epoxy. In the scope of this paper, we present a proof-of-concept in vivo experiment for recording ECG from an avian animal model under local anesthesia to verify the electrode performance. Simultaneous recording with a commercial device validated the measurements, demonstrating promising accuracy in heart rate and breathing rate monitoring. This novel technology could open avenues for the mass manufacturing of miniaturized ECG implants.Clinical relevance- A novel manufacturing process and an implantable system are presented for continuous physiological monitoring of animals to be used by veterinarians, animal scientists, and biomedical researchers with potential future applications in human health monitoring.