Electronic Sensor Devices Research Articles

The Use of Electronic Sensor Device to Augment Ligament Balancing Leads to a Lower Rate of Arthrofibrosis After Total Knee Arthroplasty

BackgroundTotal knee arthroplasty (TKA) is a highly successful surgery shown to improve quality of life. One of the more common known complications of TKA is early arthrofibrosis requiring manipulation under anesthesia (MUA). This investigation evaluates the incidence of arthrofibrosis before and after the implementation of an electronic sensor device used to assist with ligament balancing. MethodsSix hundred ninety TKAs performed without sensor use were compared to a cohort of 252 TKAs performed with sensor usage. ResultsPrior to usage, there was a 5% rate of MUA after TKA, while after implementation, the MUA rate went down to 1.6% (P = .004). Ligament balancing using sensor assistance led to a statistically significant decrease in MUA in this cohort of patients. An odds ratio analysis also demonstrated that non-sensor patients had a 3.2× higher likelihood of requiring MUA than the sensor patients. ConclusionThe use of an electronic sensor device during trialing of TKA with resultant improved ligamentous balancing led to a statistically significant reduction in the rate of MUA in this cohort of patients. This type of approach to ligamentous balancing may continue to show evidence of improved clinical outcomes.

High Power Glucose/O2 Biofuel Cell Constructed from MgO-Temlated Carbon Modified Carbon Cloth

Enzymatic biofuel cells (EBFCs) based on enzyme electrocatalysts are devices to directly convert chemical energy of glucose and alcohol to electronical energy. EBFCs gather attention as a power source of wearable electronic sensor devices because they have high biocompatibility. In this paper, we report a glucose/O2 EBFC using flexible carbon cloth electrodes modified with mesoporous carbon particle, which shows high power density as high as 2 mW cm-2. Moreover, the capacity of the BFCs can be controlled by the mole number of glucose added. Porous carbon electrode was fabricated by modifying the MgO-templated mesoporous carbon (MgOC) on carbon cloth in order to enlarge surface area and to immobilize enzyme and redox mediator on electrode surface. MgOC is a kind of pore size-controlled porous carbon; mesopore size can be controlled by alternating the MgO template size. For the anode catalyst, flavin adenine dinucleotide dependent glucose dehydrogenase (FAD-GDH) from Aspergillus terreus was used. Naphthoquinones (NQ) were used as anode mediator. FAD-GDH and NQ were modified on the anode 0.19 and 1.5 mg cm-2, respectively. For the oxygen-reducing cathode, bilirubin oxidase (BOD) was used as enzyme, and 2,2’-azinobis(3-ethylbenzothiazoline-6-sulfonic acid ammonium salt) (ABTS) as mediator. BOD and ABTS were modified on the cathode 1.25 and 1.25 mg cm-2, respectively. 1.0 M phosphate buffer (pH = 7.0) was used as an electrolyte. A cellophane sheet was sandwiched between the anode and cathode as a separator. Figure 1 shows the cell power (solid lines) and cell voltage (broken lines) as a function of current density of the EBFCs. The maximum output power density of BFCs using 1,2-NQ and 1,4-NQ for anode mediators were 1.69 and 2.06 mW cm-2, receptively, because the redox potential of 1,4-NQ is more negative than that of 1,2-NQ. Figure 2 shows the cell capacity of the BFCs as a function of glucose concentration added to the cell. The capacity of the cell increased linear with an increase of the mole number of glucose. Figure 1

Piezotronic‐based magnetoelectric sensor: Fabrication and response

In the present work, magnetoelectric‐piezotronic devices have been fabricated using exceptionally long (mm long) ZnO nano‐ and microneedles grown by the simple and versatile flame transport synthesis approach. The piezotronic response to an applied magnetic field has been investigated for state of the art magnetoelectric (ME) sensors containing AlN and PZT as piezoelectric phase as well as sensors based on ZnO nano‐ and microneedles, which are among the best described materials in terms of piezotronic applications. The current voltage (I–V) characteristics of the fabricated electronic sensor devices have been measured to understand the individual contributions of the piezoelectric and semiconducting properties. The experimentally obtained correlations between the piezotronic effect and the I–V responses have been fitted using appropriate theoretical models which have been discussed in detail. The current observations demonstrate that ME based piezotronic sensing devices have complementary roles, on one hand, the ME principle helps to get a better understanding of the piezotronic nature of quasi one dimensional (Q1D) ZnO nano‐ and microneedles, and on the other hand, the integration of a piezotronic effect leads to an improved sensitivity of the ME devices and hence to a better quality of ME sensors.

Antibody- and Label-Free Phosphoprotein Sensor Device Based on an Organic Transistor.

An antibody- and label-free detection of a phosphoprotein (α-casein) has been achieved using an organic field-effect transistor (OFET)-based sensor. The fabricated OFET device possesses an extended-gate electrode functionalized with an artificial phosphoprotein receptor (Zn(II)-dipicolylamine complex, Zn(II)-DPA). It is shown that the OFET responds to the molecular recognition processes involving the Zn(II)-DPA at the extended-gate electrode. The binding of α-casein to the receptor in a HEPES solution results in an analyte-specific changes of the drain current of the OFET. The successful demonstration of the antibody- and label-free detection using the OFET could pave the way to the development of low-cost, disposable, and portable electronic sensor devices.

Usability of a gravity- and tilt-compensated sensor with data logging function to measure posturing compliance in patients after macular hole surgery: a pilot study

To investigate the use of a small gravity- and tilt-compensated, head-fixed sensor with data-logging function to measure compliance and head posture of patients after macular hole surgery based on the recommendation of a face-down position. Main outcome measures were the median inclination, the times with correct or incorrect head position and the acceptance/annoyance of a data-logging device. A small battery-driven electronic sensor device with gravity and tilt compensations was placed within a plastic box and fixed on a patient's head with a headband. Face-down position data were logged every half second for 24 h after macular hole surgery and were stored on a memory card. Thirteen patients were involved (seven females, six males, median age, 68 years, range, 50-75 years), two cases with early dropout. Ten of 11 datasets could be evaluated showing a complete data record file. The average percentage for face-down >45° was 18% within 24 h and 17% in the daytime. The median inclination was -6.7° (min: -89.7° max: 90°). The sensor system was well tolerated and disturbance was rated low by all ten patients. While the patients' face-down posture considerably varied over time in extent and continuity, the assessment might lead to optimizing the patients' compliance with the optimal position. Results showed an excellent acceptance of the motion sensor.

Sniffer dogs as part of a bimodal bionic research approach to develop a lung cancer screening

Lung cancer (LC) continues to represent a heavy burden for health care systems worldwide. Epidemiological studies predict that its role will increase in the near future. While patient prognosis is strongly associated with tumour stage and early detection of disease, no screening test exists so far. It has been suggested that electronic sensor devices, commonly referred to as 'electronic noses', may be applicable to identify cancer-specific volatile organic compounds in the breath of patients and therefore may represent promising screening technologies. However, three decades of research did not bring forward a clinically applicable device. Here, we propose a new research approach by involving specially trained sniffer dogs into research strategies by making use of their ability to identify LC in the breath sample of patients.

A home automation proposal built on the Ginga digital TV middleware and the OSGi framework

Among the most promising applications provided by interactive Digital Television Systems (iDTV) are the ones that enable TV-Sets to work as the central processing unit of a house. This is supported by the extending of iDTV common functionalities making use of its processing power not only to deal with image and audio but also to execute interactive software applications. This paper proposes a new infrastructure that allows the exchange of data from the iDTV to Home Automation devices, such as sensors, mobile devices, and so on. The integration process among the involved technologies as well as each element in the proposed infrastructure is described in details. This model is supported by Open Services Gateway Initiative (OSGi), as a framework for networked devices, and the Brazilian reference middleware, Ginga. Thus it is possible to use devices services in OSGi-based Home Networks, through the Digital TV. In order to prove the model functionalities, we created validating scenarios of service management involving iDTV interaction with mobile phones and electronic sensor devices using WiFi and Bluetooth technologies.

ANALYSIS OF VOLTAGE SIGNALS BY FLICKER NOISE METHODOLOGY APPLIED ON POROUS SILICON FILMS GROWTH

The Flicker Noise Analysis methodology is applied on voltage signals recorded when the electrochemical etching of crystalline surfaces of silicon is performed. The porous silicon material resulting from this procedure is composed of nanocrystals possessing remarkable properties which can be employed in the development of optical, electronic, or biological sensor devices. As a result of the analysis, two dynamic processes during the electrochemical reaction have been identified: one related to the dissolution of the crystalline matrix and the other related to the porous morphology itself.

Flicker noise analysis of laminar voltage signals of porous silicon films

A special kind of noise analysis is applied on voltage signals recorded when the electrochemical etching of crystalline surfaces of silicon is performed. The resulting material, named porous silicon (PS), exhibits nanocrystalline formations and has interesting properties which can be employed in the development of optical, electronic or biological sensor devices. These characteristics depend mostly on the resulting morphology after etching. The flicker noise analysis is a suitable way to extract information on the dynamics of the pore formation and its correlation with morphology. This study shows some of the analysis results.

Magnetic hysteresis modeling of electronic sensor devices and components

The non-linear dependence on history of magnetic field and magnetization in ferromagnetic materials is described by statistical domain behaviour using phenomenological parameters. These parameters are related to macroscopic hysteresis features (as coercivity, initial susceptibility, saturation, and remanence), which allows fast and easy identification. Consequently, these parameters are related to spontaneous magnetization, magnetocrystalline anisotropy, magnetostriction, and microstructure geometry, using dimensionless microscopic constants. This step allows correct interpretations of the parameter dependence and the macroscopic hysteresis on stress, temperature, and direction of magnetization. Examples of model applications are the prediction of the magnetic behaviour of thin films in magnetoresistive sensors, stress dependence of magnetization in amorphous ribbons, and Barkhausen noise.

A New Analytical Device Based on Gated Ion Channels: A Peptide-Channel Biosensor

Binding of a protein at a ligand-modified ion channel can lead to closure or distortion of the channel, resulting in a digital on/off response of the ion flux. This principle could be applied as a strategy for sensor design using artificial membrane ligands or receptors. Important details of modeling and a technique of realization of the new molecular electronic sensor device are presented. The response of the sensor induced by analyte binding depends on the analyte's size and ability to close or distort the ion channel. Testing different ion channels in a typical single molecule-binding event modifies the membrane current by about 0.2 to 20 pA. The gated channel-based sensor is set up by using elements from different fields. It consists of a stable transmembrane channel (for example, a chemically engineered 6.3 helix peptide antibiotic) with a ligand covalently bound at the peptide channel entrance, an electrochemical sensor chip with a photostructurized hydrophobic polymer frame, a hydrophilic ion-conducting membrane support, a lipid membrane incorporating the engineered ion channel, and a sensitive membrane current amplifier or a sensitive fluorescence monitor. Detection of channel opening or closure can either be obtained directly by monitoring membrane conductivity or by monitoring a transient change in pH or ion concentration within the membrane compartment. This transient change can be induced by various means, and its decay is directly correlated to the ion permeability of the membrane. Nonspecific binding at a lipid membrane does not interfere with the ion flux through ion channels. This is a basic advantage of this principle compared to that of enzyme-linked immunosorbent assay (ELISA), radioimmunoassay (RIA), or hybridization of labeled DNA/RNA probes. Furthermore, because nonspecific binding events are mainly transient, specific binding events directly at the ion channel can be separated from them by evaluating the current peak time scale. Theoretically, the sensitivity of such a device can approach one molecule. Under practical conditions, the sensitivity is limited by the diffusion process of the analyte to the receptor ligand but not by the molecular electronic device. The new type of biosensor combines sensor design and technology from immunoassays and biorecognition assays with automated analysis systems and knowledge from the field of nanotechnology. Based on the detection principle, miniaturized portable sensor chips with either electronic or optical detection are under construction. These may have capabilities exceeding those of existing analytical instruments (for example, ELISA tests, medical analyzer, and high-pressure liquid chromatography [HPLC].