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The lightweight, low-density, and low-cost natural polymers like cellulose, chitosan, and silk have good chemical and biodegradable properties due to their individually unique structural and functional elements. However, the mechanical properties of these polymers differ from each other. In this scenario, chitosan lacks good mechanical properties than cellulose and silk. The synthesis of nano natural polymer and reinforcement with suitable chemical compounds as the development of nanocomposite gives them promising multidisciplinary applications. Many kinds of research are already published with innovative bio-derived polymeric functional materials (Bd-PFM) applications. Most research interest is carried out on health concerns. Lots of attention has been paid to biomedical applications of Bd-PFM as biosensors. This review aims to provide a glimpse of the nanostructures Bd-PFM biosensors. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel PENG using PVDF blended with crab shell powder (CS-NFs) was fabricated via electrospinning for flexible energy harvesting. • Enhanced piezoelectric performance is achieved due to the piezoelectric properties of chitin and its interaction with PVDF β-phase. • Incorporation of 1.5 wt.% CS-NFs improved the output, generating up to 19 V under mechanical deformation for energy harvesting. • This PENG can monitor respiratory and power low-energy devices, offering a sustainable, biocompatible, and eco-friendly sensors. Wearable piezoelectric nanogenerators (PENGs) are increasingly significant in healthcare and energy harvesting applications due to their ability to convert mechanical energy into electrical signals. In this study, we developed PENGs by incorporating crab shell powder (CS-NFs) into electrospun polyvinylidene fluoride (PVDF) nanofibers to enhance their piezoelectric properties. The PVDF-CS-NFs (PC-NFs) composites were evaluated for structural, thermal, and piezoelectric performance. The 1.5 wt% CS-NFs composite exhibited a notable improvement, with a maximum output voltage of 19 V under mechanical deformation, significantly higher than pristine PVDF NFs. Furthermore, the device demonstrated excellent sensitivity in real-time respiratory monitoring when applied to various body locations, including the chest, throat, and mask. Additionally, the PC-NFs-based PENGs were capable of charging a 2.2 µF capacitor to 2 V within 180 s and powering 56 LEDs. These results underscore the potential of using sustainable crab shell waste in biocompatible, eco-friendly piezoelectric devices for wearable sensors and energy harvesting applications. [ABSTRACT FROM AUTHOR]

AbstractCoronary heart disease (CHD) is a significant global health concern, necessitating continuous advancements in treatment modalities to improve patient outcomes. Traditional Chinese medicine (TCM) offers alternative therapeutic approaches, but integration with modern biomedical technologies remains relatively unexplored. This study aimed to assess the efficacy of a combined treatment approach for CHD, integrating traditional Chinese medicinal interventions with modern biomedical sensors and stellate ganglion modulation. The objective was to evaluate the impact of this combined treatment on symptom relief, clinical outcomes, hemorheological indicators, and inflammatory biomarkers. A randomized controlled trial was conducted on 117 CHD patients with phlegm-turbidity congestion and excessiveness type. Patients were divided into a combined treatment group (CTG) and a traditional Chinese medicinal group (CMG). The CTG group received a combination of herbal decoctions, thread-embedding therapy, and stellate ganglion modulation, while the CMG group only received traditional herbal decoctions. The CTG demonstrated superior outcomes compared to the CMG across multiple parameters. Significant reductions in TCM symptom scores, improved clinical effects, reduced angina manifestation, favorable changes in hemorheological indicators, and decreased serum inflammatory biomarkers were observed in the CTG post-intervention. The combination of traditional Chinese medicinal interventions with modern biomedical sensors and stellate ganglion modulation has shown promising results in improving symptoms, clinical outcomes, and inflammatory markers in CHD patients. This holistic approach enhances treatment efficacy and patient outcomes. Further research and advancements in sensor technology are needed to optimize this approach. [ABSTRACT FROM AUTHOR]

This study multifunctional wearable bioelectronics (MWBs) integrated with a piezoelectric sensor and a micropatterned temperature sensor for accurate detection of human physiological signals. Piezoelectric nanocomposite uniformity, stretchability, and adhesion is improved through the functionalization of nanoparticles with glycidyl silane and nonionic surfactants dispersion in the organic polymer matrix. Additionally, crack‐free nanometal layers are deposited on the nanocomposite interface with high adhesion by thiol silane functionalization and oxygen plasma treatment. The MWBs exhibit a temperature sensitivity of 7.1 Ω °C−1 (R2 of 0.999) between 30 °C to 40 °C, a pressure sensitivity of 72 mV kPa−1 (R2 of 0.998) within 0.5 kPa to 10 kPa, and a stable mechanical durability. MWBs have demonstrated to detect subtle pulse waveforms at an arm‐mimicking phantom and human skin, respectively. Furthermore, MWBs are applied to analyze physiological signal characteristics caused by human stress, demonstrating its potential for use in healthcare electronics in various medical applications. [ABSTRACT FROM AUTHOR]

Introduction: Suture tension has a direct influence on the sutured tissue. For abdominal wall closure, suture tension should be optimal without causing tissue necrosis, which can result in surgical site infection or incisional hernia. The purpose of the present study is to evaluate a device that can measure suture tension in-situ and in real-time. Materials and methods: A cheap, commercially available analog-to-digital converter was used, in conjunction with a force sensing resistor. A sensor probe housing was designed and 3D-printed. In order to test the sensor, a mechanical, computer controlled human abdominal wall model called the AbdoMAN was used. Results: An implantable suture tension sensor was developed, keeping cost-effectiveness in mind. This sensor can translate tension in the suture into a downward force, applied to the force sensing resistor. The sensor's raw readout was characterized using a set of weights, from which a formula correlating the readout to a specific force, was derived. Preliminary validation was successfully performed using the AbdoMANmodel, which showed a progressive rise in suture tension when the intra-abdominal pressure was artificially increased over time. Conclusion: The implantable suture tension sensor appeared to be capable of recording real time changes in suture tension, and the. validation process of this sensor has been initiated. With the information from devices like this, a much better understanding of the issues at play in the development of incisional hernia can be gained.

Schistosomiasis, typically characterized by chronic infection in endemic regions, has the potential to affect liver tissue and pose a serious threat to human health. Detecting and screening for this disease early on is crucial for its prevention and control. However, existing methods encounter challenges such as low sensitivity, time-consuming processes, and complex sample handling. To address these challenges, we report a soluble egg antigen (SEA)-based functionalized gridless and meander-type AlGaN/GaN high electron mobility transistors (HEMT) sensor for the highly sensitive detection of antibodies to Schistosoma japonicum. Immobilization of the self-assembled membrane on the gate surface was verified using a semiconductor parameter analyzer, scanning electron microscope (SEM), and atomic force microscopy (AFM). The developed biosensor demonstrates remarkable performance in detecting anti-SEA, exhibiting a linear concentration range of 10 ng/mL to 100 μg/mL and a sensitivity of 0.058 mA/log (ng/mL). It also exhibits similar excellent performance in serum systems. With advantages such as rapid detection, high sensitivity, miniaturization, and label-free operation, this biosensor can fulfill the requirements for blood defense. [ABSTRACT FROM AUTHOR]

In this paper, a novel design of photonic crystal fiber (PCF) biosensor based on surface plasmon resonance (SPR) is introduced and analyzed for cancer cell detection. The full vectorial finite element method (FVFEM) is used throughout the numerical analysis of the suggested biosensor. The reported PCF has a V-shaped surface that is coated with ZrN as a plasmonic material. A coupling occurs between the core guided mode and surface plasmon mode SPM which depends on the studied analyte. Such a coupling is improved by using the suggested V-shape geometry which increases the sensor sensitivity.The geometrical parameters are optimized to achieve high sensor sensitivity. The proposed biosensor has high optical sensitivity of 6214.28, 3800, and 5008.33 nm/RIU, for quasi-transverse magnetic (TM), and 6000 nm/RIU, 4400 nm/RIU, and 5333.3 nm/RIU, for quasi-transverse magnetic (TE), for breast, basal, and cervical cancer cells, respectively. The reported optical sensor can pave the way for efficient and simple technique for cancer detection with low cost and high sensitivity instead of surgical and chemical techniques. [ABSTRACT FROM AUTHOR]

A comparative study of surface plasmon resonances (SPR) and optical properties of metal/dielectric/graphene multilayer films based on high conductive Ag and Cu metals is presented. For measurements of the generation of surface plasmon polaritons under the resonant condition, we involved the total internal reflection ellipsometry and direct spectroscopic ellipsometry for determining optical properties. SPR was studied in graphene/HfO2/Ag(Cu)/Cr/substrate nano-hetero-structures which contain an additional graphene surface layer for enhancement of their sensing performance. The plasmonic performance of each hybrid nano-hetero-structure is evaluated based on quality factors and propagation length of surface plasmon polaritons. The SPR in the graphene/HfO2/Ag(Cu)/Cr/substrate hybrid nano-hetero-structures demonstrate a strong correlation with the measured macroscopic optical characteristics such as the effective real dielectric function ε1(λ) and optical conductivity σ(λ) and extracted from them effective microscopic parameters: the plasma and relaxation frequencies of free electrons ωP and γ. Our results on graphene/HfO2/Ag(Cu)/Cr/substrate hybrid nano-hetero-structures indicate that the real part of the effective dielectric function ε1(λ) and optical conductivity σ(λ) generally follows effective medium approach and the stronger SPR occurs at higher values of ε1(λSPR), and the ratio of ωP2/γ and lower ones of σ (λSPR). Going forward, it appears that graphene/HfO2/Ag(Cu)/Cr/substrate hybrid nano-hetero-structure designs are more suitable for surface plasmon biomedical sensor applications because they could provide both tunability and low optical loss due to specific electronic properties of graphene.

Recent progress in innovation is making the life prosper, simpler and easier for common individual. The World Health Organization (WHO) statistics indicate that a large amount of people experience visual losses, because of which they encounter many difficulties in everyday jobs. Hence, our goal is to structure a modest, secure, wearable, and versatile framework for visually impaired to help them in their daily routines. For this, the plan is to make an effective system which will assist visually impaired people through obstacle detection and scenes classification. The proposed methodology utilizes Raspberry-Pi 4B, Camera, Ultrasonic Sensor and Arduino, mounted on the stick of the individual. We take pictures of the scene and afterwards pre-process these pictures with the help of Viola Jones and TensorFlow Object Detection algorithm. The said techniques are used to detect objects. We also used an ultrasonic sensor mounted on a servomotor to measure the distance between the blind person and obstacles. The presented research utilizes simple calculations for its execution, and detects the obstructions with a notably high efficiency. When contrasted with different frameworks, this framework is a minimal effort, convenient, and simple to wear.

In this study, we proposed a triboelectric nanogenerator (TENG) as a pressure sensor to measure the load imbalance on the tibial tray. To detect the load imbalance, we proposed a segmented quadrant design. The TENG pressure sensors with various micro-patterns, including pyramid, cylindrical, and bar patterns, are utilized to measure the axial forces with different sensitivity in different quadrants of the tibial tray. The functionality of the instrumented implant is examined through experimental testing on the package, evaluating its sensing capabilities and power harvesting. The relationship between each quadrant output and the axial force is determined, which enables characterizing the self-powered sensor performance. This relationship is then used to find the center of pressure, which is an important parameter for implant design. The detection of a shift in the center of pressure can be an early indication of loosening, which is one of the major causes of knee implant failure. In addition, we investigated the apparent power captured in resistance loads by applying a sinusoidal cyclic loading to the package harvester. Under an average walking load of 2200 N, each quadrant of the harvester-package prototype produces an apparent power of approximately 5 μ W at 1 Hz and 10 μ W at 2 Hz.

Schistosomiasis, typically characterized by chronic infection in endemic regions, has the potential to affect liver tissue and pose a serious threat to human health. Detecting and screening for this disease early on is crucial for its prevention and control. However, existing methods encounter challenges such as low sensitivity, time-consuming processes, and complex sample handling. To address these challenges, we report a soluble egg antigen (SEA)-based functionalized gridless and meander-type AlGaN/GaN high electron mobility transistors (HEMT) sensor for the highly sensitive detection of antibodies to Schistosoma japonicum. Immobilization of the self-assembled membrane on the gate surface was verified using a semiconductor parameter analyzer, scanning electron microscope (SEM), and atomic force microscopy (AFM). The developed biosensor demonstrates remarkable performance in detecting anti-SEA, exhibiting a linear concentration range of 10 ng/mL to 100 μg/mL and a sensitivity of 0.058 mA/log (ng/mL). It also exhibits similar excellent performance in serum systems. With advantages such as rapid detection, high sensitivity, miniaturization, and label-free operation, this biosensor can fulfill the requirements for blood defense.

The β -phase poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE), 70/30] copolymer ferroelectric films were fabricated by a sol–gel method. The electrical dielectric permittivity in the frequency range of 1 0 2 - 1 0 6 Hz was derived from capacitance and dielectric loss of the P(VDF-TrFE)-based capacitor. It was found that the real dielectric permittivity decreases with the frequency due to the relaxation arising from interfacial polarization. Furthermore, optical constants have been extracted by fitting ultraviolet-infrared ellipsometric spectra with a three-layered structure (air/film/Si) and dielectric models. In the transparent region, the refractive index value is about 1.42. In addition, some main first-order infrared-active modes (3A 1 and 3B 2) and the corresponding structure vibrations are explained. Particularly, the A 1 mode (∼ 877.4 cm−1) comes from the CF 2 /CC symmetric stretching. The B 2 mode (∼ 840.4 cm−1) arises from CH 2 rocking and CF 2 antisymmetric stretching. The results are helpful for the ferroelectric P(VDF-TrFE)-based flexible photoelectronic biomedical sensor. [Display omitted] • A high quality β -P(VDF-TrFE) ferroelectric film was deposited by a sol–gel method. • Electrical dielectric permittivity of β -P(VDF-TrFE) films is obtained in 102–106 Hz. • Optical constants are extracted in a wide range of 200 nm–15 μ m. [ABSTRACT FROM AUTHOR]

In this paper, a gold/graphene/Ti3C2Tx-MXene hybrid layered D-type photonic crystal fiber (PCF) design based on surface plasmon resonance (SPR) sensors is proposed for cancer cell detection. This design uniquely combines gold, graphene, and Ti3C2Tx-MXene materials to achieve a synergistic effect, significantly enhancing the sensitivity and specificity of the sensor. The full vector finite element method (FVFEM) is used for the entire numerical analysis of the proposed biosensor. The cladding of the D-type PCF has a hexagonal arrangement of air holes. In the first cladding, the two air holes closest to the metal layer are narrowed down to enhance the plasma wave and provide an efficient leakage channel. The last two air holes closest to the metal layer in the same layer are enlarged to limit light scattering and couple more energy to the surface plasmon polariton (SPP) mode. The sensitivity of the sensor improves by using these different diameter air holes and coating the D-type PCF surface with a hybrid gold/graphene/Ti3C2Tx-MXene layer. The geometrical parameters are optimized to obtain higher sensor sensitivity. The corresponding wavelength sensitivities are 3000 nm/RIU for Basal cells, 5000 nm/RIU for HeLa cells (Henrietta Lacks cells), 5714 nm/RIU for Jurkat cells (Human T lymphocyte cells), 7143 nm/RIU for PC12 cells (Pheochromocytoma cells), 8571 nm/RIU for MDA-MB-231 cells (Breast cancer cells), and 9286 nm/RIU for MCF-7 cells (Michigan Cancer Foundation-7, a breast cancer cell line), respectively, confirming the excellent performance of the proposed sensor. The sensor proposed paves the way for efficient, simple, low-cost, and highly sensitive cancer detection techniques that could replace surgical and chemical techniques. [ABSTRACT FROM AUTHOR]

The development of a biomedical sensor involves an extremely sensitive optoelectronics system whose foundations lie on intracavity absoprtion spectroscopy. In order to make it convenient for technical reasons to use this application based utility, we implement dual mode competition. All of the components in this system must be investigated in detail. This work concerns with the design of the optical receiver which is mandatory to understand and analyze the received signal. This has been effectively done by designing an inexpensive system which replaces the existing Agilent based setup. Next, the performance of the system has been investigated by using an important parameter Relative Intensity Noise (RIN). The variation of injection current and temperature and their subsequent effect on RIN has been comprehensively examined. This has been enhanced by an investigation of RIN as subject to the mode positions (values of wavelengths) at which the framework is being operated. Through these considerations, the system's behaviour is understood in a much better way as they lead to an improvement in the sensor's realization with high sensitivity and stability.

Load sensing total knee replacement (TKR) implants are useful tools for monitoring prosthesis health and providing quantitative data to support patient claims of pain or instability. However, powering such devices throughout the entire life of the knee replacement is a challenge, and self-powered telemetry via energy harvesting is an attractive solution. In this article, we implemented vertical contact mode triboelectric energy harvesters inside a knee implant package to generate the power required for embedded digitization and communications circuitry. The harvesters produce small-scale electric power from physiologically relevant loads transmitted through the knee. Experiments were performed on a joint motion simulator with an instrumented package prototype between the polyethylene bearing and tibial tray. The amplitude and the pattern of the power output varied with the input loadings. Under sinusoidal loading the maximum apparent power harvested was around 7 μW at (50–2000)N whereas, under vertical compressive gait loading the harvesters generated around 10 μW at average human knee loads of (151–1950)N and 20 μW when the maximum applied load was increased by 25%. Full six degrees-of-freedom gait load/motions at 0.67 Hz produced 50% less power due to the slower loading rate. The results show the potential of developing a triboelectric energy harvesting-based self-powered instrumented knee implant for long-term in vivo knee joint force measurement. [ABSTRACT FROM AUTHOR]

This study describes the design and characterization of a highly sensitive THz refractive index-based metamaterial sensor for the detection of biological samples. The proposed ultra-miniaturized THz sensor is constructed using a fan-shaped resonator enclosed within a square loop. The proposed sensor has a footprint of 0.353 $\lambda$ eff × 0.353 $\lambda$ eff where $\lambda$ eff is the wavelength calculated at the operating frequency of 4.87 THz. The sensitivity of the THz sensor is estimated using the absorption characteristics of the metamaterial. The estimated free space absorptivity is 99.9%. The proposed sensor is polarization insensitive due to the rotational symmetry and it is angularly stable up to 60°. The performance of the sensor is evaluated for different materials and biomedical samples. The results indicate that the proposed sensor has an average sensitivity of 1936 GHz/ Refractive Index Unit (RIU). Furthermore, the influence of the sample thickness is analysed, and the results are presented. From the results, it is inferred that the proposed THz sensor has a good Figure of Merit (FoM) and is suitable for chemical sensing, including the nucleic acids and other components present in the biological samples. [ABSTRACT FROM AUTHOR]

The objectives of this study are to experimentally investigate the effects of the dielectric material and the package stiffness on the durability and the efficiency of a previously developed triboelectric-based instrumented knee implant prototype. The proposed smart knee implant may provide useful information about prosthesis health and its functionality after a total knee replacement (TKR) by routine monitoring of tibiofemoral load transfer without the need for any external power source. The triboelectric powered load sensing by the proposed TKR system needs to be functional throughout the entire life of a knee replacement. The power output of the triboelectric system depends on the surface charge generations and accumulations on its dielectric material, and the force that transmits through its housing into the tribo-materials. The properties of the dielectric material and the package stiffness can significantly influence the reliability of the proposed device. For such a TKR system, a compliant mechanism with the ideal material selection can improve its state of the art. We investigated the performance of three vertical contact mode triboelectric generators made with three different dielectric materials: polydimethylsiloxane (PDMS), fluorinated ethylene propylene (FEP), and polytetrafluoroethylene (PTFE). To investigate the effect of package stiffness, we tested two Ti-PDMS-Ti harvesters inside a polyethylene and a Ti6Al4V package. At 1500 N of sinusoidal loads, the harvesters could generate 67.73 µW and 19.81 µW of mean apparent power in parallel and single connections in the polyethylene package, which was 32 and 17 times greater than the power recorded in the Ti assembly, respectively. [ABSTRACT FROM AUTHOR]

This paper presents the design and evaluation of a multi-band terahertz (THz) metamaterial-based biomedical (BioMed) sensor for blood component detection such as Deoxyribonucleic acid (DNA), Ribonucleic acid (RNA), plasma, water, Red Blood Cells (RBC), White Blood Cells (WBC) and haemoglobin. The proposed THz sensor is a multimode resonator with concentric square loops enclosing concentric octagonal loops. The proposed sensor has a metamaterial feature with a footprint of 0.164λeff × 0.164λeff. The THz sensor operates between 1 and 2 THz with four independently tunable operating bands, viz. 0.33, 0.90, 1.42 and 1.85 THz. The sensitivity of the THz sensor is estimated using the absorption characteristics, and the estimated average absorptivity is 99% for the proposed BioMed sensor. The THz sensor has a rotational symmetry offering both polarization and angular stability (up to 60°). The performance of the sensor is evaluated for different BioMed samples providing unique refractive indices. Furthermore, the impact of sample thickness on the sensor performance has been evaluated and presented. From the results, it is inferred that the proposed THz sensor is suitable for nucleic acids and other components detection in blood samples. [ABSTRACT FROM AUTHOR]

This paper presents a high-precision biomedical sensor system with a novel analog-frontend (AFE) IC and error correction by machine learning. The AFE IC embeds an analog-to-digital converter (ADC) architecture called successive stochastic approximation ADC. The proposed ADC integrates a stochastic flash ADC (SF-ADC) into a successive approximation register ADC (SAR-ADC) to enhance its resolution. The SF-ADC is also used as a digitally controlled variable threshold comparator to provide error correction of the SAR-ADC. The proposed system also calibrates the ADC error using the machine learning algorithm on an external PC without additional power dissipation at a sensor node. Due to the flexibility of the system, the design complexity of an AFE IC can be relaxed by using these techniques. The target resolution is 18 bits, and the target bandwidth (without digital low-pass filter) is about 5 kHz to deal with several types of biopotential signals. The design is fabricated in a 130-nm CMOS process and operates at 1.2-V supply. The fabricated ADC achieves the SNDR of 88 dB at a sampling frequency of 250 kHz by using the proposed calibration techniques. Due to the high-resolution ADC, the input-referred noise is 2.52 μVrms with a gain of 28.5 dB.

Compact and low-cost opto-biomedical sensing systems today are ubiquitously available for measuring the oxygen saturation in blood. The oxygen saturation is derived by a complex, usually not well defined analytical process from the optical absorption of tissue at different wavelengths. The amount of information, which is originally contained in absorption measurements, is drastically reduced by this circumstance. However, the reliability of the analytical process as well as the influence of external parameters like blood pressures on the experimental uncertainty of such systems are widely unknown. Thus, to explore the experimental uncertainty quantitatively, original experimental data have to be used. In commercial systems, however, these data are usually not accessible. Therefore, test systems with full access to original absorption data are necessary. In this work, we develop and describe a test system consisting of color filters and a charge-coupled device (CCD) image sensor, which has substantial advantages in comparison to usually used systems based on multi-color light-emitting diodes (LEDs). Color filters with well-defined filter functions allow for a higher spectral resolution, and will finally guide the way to multi-spectral analysis of blood absorption measurements with reduced uncertainty. [ABSTRACT FROM AUTHOR]

A self-powered and durable pressure sensor for large-scale pressure detection on the knee implant would be highly advantageous for designing long-lasting and reliable knee implants as well as obtaining information about knee function after the operation. The purpose of this study is to develop a robust energy harvester that can convert wide ranges of pressure to electricity to power a load sensor inside the knee implant. To efficiently convert loads to electricity, we design a cuboid-array-structured tribo-pizoelectric nanogenerator (TPENG) in vertical contact mode inside a knee implant package. The proposed TPENG is fabricated with aluminum and cuboid-patterned silicone rubber layers. Using the cuboid-patterned silicone rubber as a dielectric and aluminum as electrodes improves performance compared with previously reported self-powered sensors. The combination of 10 w t % dopamine-modified BaTiO 3 piezoelectric nanoparticles in the silicone rubber enhanced electrical stability and mechanical durability of the silicone rubber. To examine the output, the package-harvester assemblies are loaded into an MTS machine under different periodic loading. Under different cyclic loading, frequencies, and resistance loads, the harvester's output performance is also theoretically studied and experimentally verified. The proposed cuboid-array-structured TPENG integrated into the knee implant package can generate approximately 15 μ W of apparent power under dynamic compressive loading of 2200 N magnitude. In addition, as a result of the TPENG's materials being effectively optimized, it possesses remarkable mechanical durability and signal stability, functioning after more than 30 000 cycles under 2200 N load and producing about 300 V peak to peak. We have also presented a mathematical model and numerical results that closely capture experimental results. We have reported how the TPENG charge density varies with force. This study represents a significant advancement in a better understanding of harvesting mechanical energy for instrumented knee implants to detect a load imbalance or abnormal gait patterns., (© 2024 The Author(s). Published by IOP Publishing Ltd.)

Introduction: Suture tension has a direct influence on the sutured tissue. For abdominal wall closure, suture tension should be optimal without causing tissue necrosis, which can result in surgical site infection or incisional hernia. The purpose of the present study is to evaluate a device that can measure suture tension in-situ and in real-time., Materials and Methods: A cheap, commercially available analog-to-digital converter was used, in conjunction with a force sensing resistor. A sensor probe housing was designed and 3D-printed. In order to test the sensor, a mechanical, computer controlled human abdominal wall model called the AbdoMAN was used., Results: An implantable suture tension sensor was developed, keeping cost-effectiveness in mind. This sensor can translate tension in the suture into a downward force, applied to the force sensing resistor. The sensor's raw readout was characterized using a set of weights, from which a formula correlating the readout to a specific force, was derived. Preliminary validation was successfully performed using the AbdoMANmodel, which showed a progressive rise in suture tension when the intra-abdominal pressure was artificially increased over time., Conclusion: The implantable suture tension sensor appeared to be capable of recording real time changes in suture tension, and the. validation process of this sensor has been initiated. With the information from devices like this, a much better understanding of the issues at play in the development of incisional hernia can be gained., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

Purpose: After closure of laparotomies, sutures may pull through tissue due to too high intra-abdominal pressure or suture tension, resulting in burst abdomen and incisional hernia. The objective of this study was to measure the suture tension in small and large bites with a new suture material. Methods: Closure of the linea alba was performed with small bites (i.e., 5 mm between two consecutive stitches and 5 mm distance from the incision) and large bites (i.e., 10 mm × 10 mm) with Duramesh™ size 0 (2 mm) and PDS II 2-0 in 24 experiments on six porcine abdominal walls. The abdominal wall was fixated on an artificial computer-controlled insufflatable abdomen, known as the 'AbdoMan'. A custom-made suture tension sensor was placed in the middle of the incision. Results: The suture tension was significantly lower with the small bites technique and Duramesh™ when compared with large bites (small bites 0.12 N (IQR 0.07–0.19) vs. large bites 0.57 N (IQR 0.23–0.92), p < 0.025). This significant difference was also found in favour of the small bites with PDS II 2-0 (p < 0.038). No macroscopic tissue failure was seen during or after the experiments. Conclusion: Closure of the abdominal wall with the small bites technique and Duramesh™ was more efficient in dividing suture tension across the incision when compared to large bites. However, suture tension compared to a conventional suture material was not significantly different, contradicting an advantage of the new suture material in the prevention of burst abdomen and incisional hernia during the acute, postoperative phase. [ABSTRACT FROM AUTHOR]

The paper presents an approach to noninvasively measure pulse wave delay and velocity by means of two multiplexed fiber-optic Fabry-Perot interferometric sensors interrogated by means of spectral interferometry. The pulse wave signals were measured with 1 kHz sampling rate. The obtained optical path difference resolutions are on the order of tens picometers, which allowed the pulse wave signal features as small as 100 pm to be clearly observed in the demodulated waveforms. The pulse wave velocity between different arteries was measured, demonstrating good agreement with the known data, where applicable. The paper also presents a mathematical model based on Cramer-Rao approach, describing the fundamental resolution limits of the pulse wave delay measurement. The derived mathematical model is not limited to fiber-optic pulse wave sensors and can be used for estimating the performance of other systems, such as photoplethysmographic and ultrasound. The reported work paves the way to development of novel all-optical non-invasive systems for medical diagnostics and vital signs monitoring, including portable devices. [ABSTRACT FROM AUTHOR]

In order to design and manufacture a reliable biomedical sensor, sensitive tests have to be performed. This is of superlative importance as it has to be used for the general public. Keeping this into account, the test mechanism of such an extremely sensitive sensor is being done that involves exhaustive protocols regarding the checkup and performance of specific parameters. The control system of the setup involves optoelectronic components like fibre Bragg gratings, optical amplifiers and optical couplers that have been mechanized by implementing newly developed algorithms in software (LabView and MATLAB). Performance has been classified by hysteresis curves, scrutiny of timing analysis and investigation of error deviation. This guarantees the credibility and trustworthiness of the said sensor and aids to check out its performance from time to time. This also opens up vistas for further extensions of the project and ongoing applications which has been postulated in the conclusion. [ABSTRACT FROM AUTHOR]

I develop a conceptual framework based on a systematic and comprehensive literature review on wearable Internet of Things healthcare systems. Building my argument by drawing on data collected from Accenture, Ericsson ConsumerLab, GE Healthcare, McKinsey & Co., MIT Technology Review Insights, PwC, and Statista, I performed analyses and made estimates regarding patients willing to use digital devices at home and visit with doctors virtually and to have surgery performed by a robot instead of a doctor. The data for this research were gathered via an online survey questionnaire and were analyzed through structural equation modeling on a sample of 4,600 respondents. [ABSTRACT FROM AUTHOR]

Magnetic micro- and nanoparticles (MPs)-based composite materials are widely used in various applications in electronics, biotechnology, and medicine. This group of silicone composites have advantageous magnetic and mechanical properties as well as sufficient flexibility and biocompatibility. These composites can be applied in medicine for biological sensing, drug delivery, tissue engineering, and as remote-controlled microrobots operating in vivo. In this work, the properties of polydimethylsiloxane (PDMS)-based composites with different percentages (30 wt.%, 50 wt.%, 70 wt.%) of NdFeB microparticles as a filler were characterized. The novelty of the work was to determine the influence of the percentage of MP content and physiological conditioning on the properties of the PDMS-MP composites after in vitro incubation. An important essence of the work was a comprehensive study of the properties of materials important from the point of view of medical applications. Materials were tested before and after conditioning in 0.9 wt.% NaCl solution at a temperature of 37 °C. Several studies were carried out, including thermal, physicochemical, and rheological tests. The results show that with an increase of the incubation time, most of the measured thermal and physicochemical parameters decreased. The presence of the magnetic filler, especially at a concentration of 70 wt.%, has a positive effect on thermal stability and physicochemical and rheological properties. The performed tests provided important results, which can lead to further research for a broader application of magnetic composites in the biomedical field.

Hyoid bone movement is an important physiological event during swallowing that contributes to normal swallowing function. In order to determine the adequate hyoid bone movement, clinicians conduct an X-ray videofluoroscopic swallowing study, which even though it is the gold-standard technique, has limitations such as radiation exposure and cost. Here, we demonstrated the ability to track the hyoid bone movement using a non-invasive accelerometry sensor attached to the surface of the human neck. Specifically, deep neural networks were used to mathematically describe the relationship between hyoid bone movement and sensor signals. Training and validation of the system were conducted on a dataset of 400 swallows from 114 patients. Our experiments indicated the computer-aided hyoid bone movement prediction has a promising performance when compared with human experts’ judgements, revealing that the universal pattern of the hyoid bone movement is acquirable by the highly nonlinear algorithm. Such a sensor-supported strategy offers an alternative and widely available method for online hyoid bone movement tracking without any radiation side-effects and provides a pronounced and flexible approach for identifying dysphagia and other swallowing disorders.

Pulse wave (PW) measurement is a highly prominent technique, used in biomedical diagnostics. Development of novel PW sensors with increased accuracy and reduced susceptibility to motion artifacts will pave the way to more advanced healthcare technologies. This paper reports on a comparison of performance of fiber optic pulse wave sensors, based on Fabry–Perot interferometer, fiber Bragg grating, optical coherence tomography (OCT) and singlemode-multimode-singlemode intermodal interferometer. Their performance was tested in terms of signal to noise ratio, repeatability of demodulated signals and suitability of demodulated signals for extraction of information about direct and reflected waves. It was revealed that the OCT approach of PW monitoring provided the best demodulated signal quality and was most robust against motion artifacts. Advantages and drawbacks of all compared PW measurement approaches in terms of practical questions, such as multiplexing capabilities and abilities to be interrogated by portable hardware are discussed.

A novel temperature transduction method using the high-frequency electrochemical impedance between a pair of microelectrodes exposed to aqueous solution is reported. The solution resistance of an aqueous ionic solution is highly temperature dependent, and the electrochemical impedance between two microelectrodes is dominated by solution resistance when measured at the appropriate frequency. Therefore, precise measurements of electrochemical impedance at the proper frequency in a two-electrode system can be used to transduce solution temperature. To demonstrate this method, a temperature sensor composed of two thin-film platinum electrodes on a freestanding Parylene C substrate was designed and fabricated. A platinum resistance temperature detector was co-fabricated to provide a simple means of benchmarking against an existing standard. Transduction via electrochemical impedance was achieved by measuring the real part of impedance at the frequency where phase was minimized. Fluid temperature was transduced between 15°C and 50°C with high sensitivity (−1.21%/°C) and resolution (0.02°C). A $4\times $ improvement in sensitivity and resolution over the conventional platinum resistance temperature detector was achieved. The sensor design described here features flexible construction with inert materials which facilitates future use in biomedical or microfluidic applications. [2019-0190] [ABSTRACT FROM AUTHOR]

Since the nanogenerator (NG) was invented in 2006, it has been successfully developed and utilized to harvest various forms of mechanical energy in vivo. The NGs promote the progress of self-powered biomedical devices. Moreover, NGs can also be used as sensors to detect a variety of important physiological signals, which brings us closer to real-time, high-fidelity monitoring of physical and pathological information. This paper summarizes the in vivo applications of NGs as biomedical sensors, including in cardiac sensors, respiration sensors, blood pressure sensors, gastrointestinal sensors and bladder sensors. However, there are still many challenges in using NGs as sensors in vivo. For example, how can we minimize and encapsulate the NGs, how can we increase the stability and reliability during long-term detection, and how can we establish a corresponding relationship between the NG's electrical output and the physiological signals. It is also critical to follow the medical principles more closely in the development of self-powered sensors in the future. We believe that the self-powered sensors would promote the development of the next-generation healthcare monitoring systems. [ABSTRACT FROM AUTHOR]

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Abstract The development of nanogenerators that is capable of converting mechanical energy into electricity could enable extraordinary advances in biomedical devices and wearable consumer electronics. Piezoelectric composites have no intricate assemblies, providing a compact and reliable alternative to energy interconversion in biomedical electronics. This work deals with the development of a new class of piezoelectric elastomer composite which is integrated multiple potential functionalities. To fully understand and exploit the unique properties of the composited material, characterisations in terms of general mechanical, dynamic mechanical, and dynamic piezoelectric experimental investigations have been conducted. Three prototypes with individual application have been successfully built up utilising the piezoelectric elastomer composite. The versatility of the composite developed in this work presents its outstanding potential in building self-powered systems or biomedical implanted sensors. Graphical abstract Image 1 [ABSTRACT FROM AUTHOR]

This paper presents a monolithic low power and fast tracking light-to-frequency converter for blood SpO $_2$ sensing. Normally, the tracking speed and the power consumption are two contradictory characteristics. However, different gain-bandwidth specifications for various ambient light intensities allow the dynamic optimization of the power consumption according to the light intensity. In this paper, the amplifier power consumption is adaptively scaled by the generated light-intensity-positively-correlated control voltage. Thus, the chip total power consumption at low light intensity is significantly decreased. Moreover, the proposed adaptive power scaling is achieved with a continuous analog domain, which does not introduce extra switching noise. The proposed light-to-frequency sensor chip is fabricated by using 0.35  ${\rm {\mu m}}$ CMOS technology with a die area of 1 × 0.9 mm $^2$. The measurement results show that the pulse light response for any light intensity is no longer than two new output square-wave cycles. The maximum total current consumption is 1.9 mA from a 3.3 V supply voltage, which can be adaptively scaled down to only 0.7 mA if the output frequency is about 25 KHz or lower. The minimum operational supply voltage of the proposed sensor chip is 2.5 V in the temperature range of –25 to 80  $^\circ$ C with 4 KV ESD level (human-body model). [ABSTRACT FROM AUTHOR]