Oscillometric blood pressure measurement: the methodology, some observations, and suggestions

Most noninvasive blood pressure (NIBP) devices use the oscillometric method. Published studies of oscillometric methodology introduced varied algorithmic approaches for determination of systolic (SBP), diastolic (DBP), and mean arterial (MAP) blood pressures. While there is a general agreement about MAP determination, controversy exists about the determination of SBP and DBP Accuracy of oscillometric devices has been questioned and validation studies have revealed problems. Several validation protocols have been developed but they are expensive and time consuming to conduct and they have their own limitations. Instruments for bench testing of NIBP devices are useful for some device functions, but they cannot perform dynamic accuracy tests. The issue of accuracy is becoming very important as health care professionals increasingly rely on electronic NIBP devices. The authors developed a compact system for acquisition of NIBP waveforms. Some representative oscillometric waveforms are introduced here to demonstrate the oscillometric method and its shortcomings. A finger photoplethysmograph (PPG) was used to demonstrate a potential improvement of SBP determination. The concept and significance of an oscillometric blood pressure waveform database is introduced and its applications are discussed.     

Medical devices manufactured from latex: European regulatory initiatives

In Europe the marketing of medical devices manufactured from latex is regulated by directives describing the essential (safety) requirements that products have to fulfill to obtain marketing approval. This paper describes the general requirements for marketing medical devices in Europe and, more specifically, the requirements for products manufactured from natural rubber latex. The requirements for marketing medical devices can be fulfilled by using the relevant harmonized European standards. These standards are regularly under revision to incorporate the latest scientific developments. For certain devices, for example, latex medical (examination and surgical) gloves, specific standards have been published. Medical devices manufactured from latex pose a serious problem because of the risk of induction of allergy both against the latex proteins inherently present (type I or immediate type allergy) and against chemicals added during processing (type IV or delayed type hypersensitivity) present as residues in the latex products. So, besides requirements for product quality in terms of barrier properties, strength, and sterility, the main focus consists of the allergy-inducing properties of the latex products. Recent developments have reopened the discussion on the value of total protein versus allergen determination in latex medical gloves. However, as long as minimal levels needed for both sensitization and elicitation have not been established, a safe maximum level for leachable proteins/allergens in latex products cannot be determined. A European Commission guidance document on the latex allergy problem is currently being drafted by experts from Competent Authorities.     

A review of Doppler ultrasound quality assurance protocols and test devices

In this paper, an overview of Doppler ultrasound quality assurance (QA) testing will be presented in three sections. The first section will review the different Doppler ultrasound parameters recommended by professional bodies for use in QA protocols. The second section will include an evaluation and critique of the main test devices used to assess Doppler performance, while the final section of this paper will discuss which of the wide range of test devices have been found to be most suitable for inclusion in Doppler QA programmes. Pulsed Wave Spectral Doppler, Colour Doppler Imaging QA test protocols have been recommended over the years by various professional bodies, including the UK's Institute of Physics and Engineering in Medicine (IPEM), the American Institute for Ultrasound in Medicine (AIUM), and the International Electrotechnical Commission (IEC). However, despite the existence of such recommended test protocols, very few commercial or research test devices exist which can measure the full range of both PW Doppler ultrasound and colour Doppler imaging performance parameters, particularly quality control measurements such as: (i) Doppler sensitivity (ii) colour Doppler spatial resolution (iii) colour Doppler temporal resolution (iv) colour Doppler velocity resolution (v) clutter filter performance and (vi) tissue movement artefact suppression. In this review, the merits of the various commercial and research test devices will be considered and a summary of results obtained from published studies which have made use of some of these Doppler test devices, such as the flow, string, rotating and belt phantom, will be presented.     

Effects of a wireless local area network (LAN) system, a telemetry system, and electrosurgical devices on medical devices in a hospital environment

Concerns have been raised about interference of wireless local area network (LAN) systems and telemetry systems with medical devices in hospitals. The authors have investigated the susceptibility of 65 electromedical devices to a wireless LAN system and a telemetry system in preselected areas of a hospital. Testing was based on the American National Standards Institute Standard C63.18. The wireless LAN system operated at 2.42 GHz with an output power of 100 mW. The telemetry system operated at 466 MHz with an output power of 4 mW. Of the 65 devices tested, only two hand-held Doppler units, a Mini Doppler Model D900 (Huntleigh Healthcare Ltd) and a Ultrasonic Doppler Model 811 (Parks Medical Electronics, Inc.), were affected by the LAN system. Placed within 10 cm of the LAN system in standby mode, both units emitted periodic high-pitched beating sounds, which could be misinterpreted as normal beating sounds from the patient. These changed to random static noise during data transmission by the LAN. Under normal conditions of use, a LAN system would never be placed this close to a medical device. The quality of data transmission from the LAN system changed from "good" to "acceptable" in the colonoscopy room. This deterioration in transmission quality could have been caused by the lead shielding in the room. Electrosurgical devices operating at 0.5 to 1 MHz did not affect the LAN system at distances up to 3 m. None of the devices was affected by the telemetry system. These findings suggest that wireless LAN systems and telemetry systems can be acceptable for use in hospitals. Nevertheless, other systems should be tested on potentially susceptible devices by the hospital before use.     

An unusual cause of recurrent syncope in a patient with implantable cardioverter defibrillator

Electromagnetic interferences (EMI) deriving from electrical devices may affect implantable cardioverter defibrillators (ICD). Improved algorithms have been developed in order to minimize adverse effects. However, caution should be still recommended in ICD recipients when handling electrical devices. Here we describe the case of an ICD patient with recurrent syncopal episodes due to inhibition of pacing by oversensing of electrical noise from a not properly grounded washing machine.     

Use of a Vacuum-Assisted Device for Fournier's Gangrene: A New Paradigm

Fournier's gangrene is a necrotizing infection of the scrotum or perineum that requires aggressive surgical debridement. Radical debridement of perineal necrotizing fasciitis can leave extensive tissue defects that are difficult to close and often require multiple surgical interventions. Vacuum-assisted closure (VAC) devices have been shown to assist in a more rapid closure of these wounds, but placement of such devices in the perineum can pose significant challenges. We have had success with use of VAC devices and report our techniques for their placement.     

Health Effects of Trace Metals in Electronic Cigarette Aerosols—a Systematic Review

Biological Trace Element Research - Electronic cigarettes (ECs) are essentially nicotine delivery devices that mimic the appearance of a conventional cigarette (CC). Lately, they have been marketed...     

Highly Efficient Materials Assembly Via Electrophoretic Deposition for Electrochemical Energy Conversion and Storage Devices

Featuring pronounced controllability, versatility, and scalability, electrophoretic deposition (EPD) has been proposed as an efficient method for film assembly and electrode/solid electrolyte fabrication in various energy storage/conversion devices including rechargeable batteries, supercapacitors, and fuel cells. High‐quality electrodes and solid electrolytes have been prepared through EPD and exhibit advantageous performances in comparison with those realized with traditional methods. Recent advances in the application of EPD materials in electrochemical energy storage and conversion devices are summarized. In particular, the parameters that influence the efficiency of an EPD process from colloidal preparation to deposition are evaluated with the aim to provide insightful guidance for realizing high‐performance electrochemical energy conversion materials and devices.     

Implantable diagnostic and therapeutic devices in children

Many advances have been made in the use of implantable diagnostic and therapeutic devices in adults. In children the indications for and diagnostic and therapeutic value of these devices still have to be determined.Our aim is to provide an overview of the clinical use of diagnostic and therapeutic devices in children. The role of implantable loop recorders (ILR), the feasibility and safety of transvenous pacing in neonates, the value of permanent pacing in children with recurrent syncope or reflex anoxic seizures and the role of implantable cardioverter defibrillator devices are highlighted with relevant case histories.     

Architecture and applications for an All-FPGA parallel computer

The Reconfigurable Computing Cluster (RCC) project has been investigating unconventional architectures for high end computing using a cluster of FPGA devices connected by a high-speed, custom network. Most applications use the FPGAs to realize an embedded System-on-a-Chip (SoC) design augmented with application-specific accelerators to form a message-passing parallel computer. Other applications take a single accelerator core and tessellate the core across all of the devices, treating them like a large virtual FPGA. The experimental hardware has also been used for basic computer research by emulating novel architectures. This article discusses the genesis of the over-arching project, summarizes results of individual investigations that have been completed, and how this approach may prove useful in the investigation of future Exascale systems.     

Driving multiple pulsed field electrophoresis devices from one personal computer

A PC has been programmed to control more than one pulsed fieldelectrophoresis device (e.g. clamped homogeneous electric field,CHEF; field inversion gel electrophoresis, FIGE). Each deviceis assumed to have a field controller requiring signals to (i)switch the field on/off, (ii) re-orient the field and (iii)invert the field. An interface between the computer parallelport and up to four devices is suggested and this was builtfrom stan dard TTL logic and optical couplers. Software hasbeen written to drive all four devices in parallel. Each pulsedfield device may have a totally independent pulse regime, maybe stopped or started at random and may be monitored at anytime during an experiment. Setting up and running each deviceis almost entirely by mouse control and frequently used pulseregimes may be saved and rapidly retrieved from hard or floppydisk. The software can be configured for any combination ofCHEF and FIGE devices.     

Structural and organisational conditions for being a machine

Although the analogy between macroscopic machines and biological molecular devices plays an important role in the conceptual framework of both neo-mechanistic accounts and nanotechnology, it has recently been claimed that certain complex molecular devices (consisting of biological or synthetic macromolecular aggregates) cannot be considered machines since they are subject to physicochemical forces that are different from those of macroscopic machines. However, the structural and physicochemical conditions that allow both macroscopic machines and microscopic devices to work and perform new functions, through a combination of elemental functional parts, have not yet been examined. In order to fill this void, this paper has a threefold aim: first, to clarify the structural and organisational conditions of macroscopic machines and microscopic devices; second, to determine whether the machine-like analogy fits nanoscale devices; and third, to assess whether the machine-like analogy is appropriate for describing the behaviour of some biological macromolecules. Finally, the paper gives an account of ‘machine’ which, while acknowledging the physicochemical and organisational differences between man-made machines and biological microscopic devices, nevertheless identifies a common conceptual core that allows us to consider the latter ‘machines’.     

Oxygen uptake rates and liver-specific functions of hepatocyte and 3T3 fibroblast co-cultures

Bioartificial liver (BAL) devices have been developed to treat patients undergoing acute liver failure. One of the most important parameters to consider in designing these devices is the oxygen consumption rate of the seeded hepatocytes which are known to have oxygen consumption rates 10 times higher than most other cell types. Hepatocytes in various culture configurations have been tested in BAL devices including those formats that involve co-culture of hepatocytes with other cell types. In this study, we investigated, for the first time, oxygen uptake rates (OUR)s of hepatocytes co-cultured with 3T3-J2 fibroblasts at various hepatocyte to fibroblast seeding ratios. OURs were determined by measuring the rate of oxygen disappearance using a ruthenium-coated optical probe after closing and sealing the culture dish. Albumin and urea production rates were measured to assess hepatocyte function. Lower hepatocyte density co-cultures demonstrated significantly higher OURs (2 to 3.5-fold) and liver- specific functions (1.6-fold for albumin and 4.5-fold for urea production) on a per cell basis than those seeded at higher densities. Increases in OUR correlated well with increased liver-specific functions. OURs (V(m)) were modeled by fitting Michaelis-Menten kinetics and the model predictions closely correlated with the experimental data. This study provides useful information for predicting BAL design parameters that will avoid oxygen limitations, as well as maximize metabolic functions.     

Magnetic Resonance Imaging Conditional Pacemakers: Rationale, Development and Future Directions

Pacemakers and other cardiac implantable electronic devices (CIEDs) have long been considered an absolute contraindication to magnetic resonance imaging (MRI), a crucial and growing imaging modality. In the last 20 years, protocols have been developed to allow MR scanning of CIED patients with a low complication rate. However, this practice has remained limited to a relatively small number of centers, and many pacemaker patients continue to be denied access to clinically indicated imaging. The introduction of MRI conditional pacemakers has provided a widely applicable and satisfactory solution to this problem. Here, the interactions of pacemakers with the MR environment, the results of MR scanning in patients with conventional CIEDs, the development and clinical experience with MRI conditional devices, and future directions are reviewed.     

In vitro study of the electromagnetic interaction between wireless phones and an implantable neural stimulator

Several clinical and laboratory studies have demonstrated electromagnetic interaction between implantable medical devices like pacemakers and cell phones being operated in close proximity. Those devices are largely now immune to phone interaction or procedures have been established to limit their interaction. The use of cell phones near people with implanted neural stimulators has not been studied. This research was initiated to investigate electromagnetic interaction between current cell phone technology and specific models of Cyberonics neural stimulators. Out of 1080 test runs conducted for this study, no interactions were observed, and it was concluded that the phone technologies examined in this study did not adversely affect the Cyberonics NeuroStar (Model 102) NeuroCybernetic Prosthesis (NCP) System. This article provides details on the experimental procedure that was used, which can also be used to test other neural stimulators and test technologies, and the results obtained.     

Experimental evaluation of environmental enrichment of sea turtles

Although behavioral studies have been conducted at zoos and aquaria for years, documentation concerning the effectiveness of environmental enrichment has dealt primarily with terrestrial animals and marine mammals. Few enrichment studies have been conducted on reptiles. For this study, behavioral observations were made on four captive sea turtles (three loggerhead, Caretta caretta, and one blind green, Chelonia mydas) with enrichment present and absent. Enrichment devices were modified for the special needs of the blind turtle. Behaviors were classified as Resting, Pattern Swimming, Random Swimming, Focused Behavior, Aggression, Hiding, Orientation, and Noncategorized Behavior. It was hypothesized that, when enrichment was present, a decrease in Resting and stereotypic Pattern Swimming would be seen along with an increase in Random Swimming and Focused Behavior. It was found that, when no enrichment devices were present, 77% of the turtles' time was spent in Resting and Pattern Swimming. When enrichment devices were provided, 88% of their time was spent in Random Swimming and Focused Behavior with only 8% spent in Pattern Swimming and Resting. Statistically, there were significant increases in Random Swimming (three of the four turtles) and Focused Behavior (4/4) and significant decreases in Resting (3/4) and Pattern Swimming (3/4) when enrichment devices were present. These results suggest that environmental enrichment is as effective with marine reptiles as has been found with other animals and should be encouraged for all captive sea turtles. Zoo Biol 26:407–416, 2007. © 2007 Wiley‐Liss, Inc.     

Bioelectrochemical fuel cells

In the past 20 years, inorganic fuel cells have been transformed from novelty devices to practical energy transfer-energy storage units. However, the advantage of the high operating efficiency afforded by these fuel cells is partially offset by (a) the limited viability and high cost of the catalysts, (b) the highly corrosive electrolytes, and (c) the elevated operating temperatures. The possibility exists to reduce some of these problems through the development of bioelectrochemical fuel cells. Such biological/electrochemical systems incorporate either microorganisms or enzymes as an active component within the specified electrode compartments. Recent studies with microorganisms as part of the anode compartment have been aimed at defining the mechanism of the observed electrochemical reactions. Recent investigations on the use of cell-free enzyme preparations in the electrode compartments have dealt primarily with developing methodology and defining mechanisms for enhancing the rate of electron transfer from the enzyme-cofactor active site to the solid electrode surface. Applications of this developing technology have been envisioned for analytical chemistry, medical devices, energy transfer, electrochemical synthesis, and detoxification. In this review, the theory and problems of bioelectrochemical fuel cells are described and related to research, both recent and proposed, for the practical development of this area.     

Annealing Process in the Refurbishment of the Plasmonic Photonic Structures Fabricated Using Colloidal Gold Nanoparticles

Solution-processible fabrication techniques have been demonstrated with promising features for realizing different types of plasmonic devices, which combine interference lithography, spin-coating of the colloidal gold nanoparticles, and subsequent annealing process at a temperature of 200–300 °C. However, the resultant device needs to be improved in the following considerations: (1) The photoresist master grating needs to be removed for the applications in optoelectronic or sensor devices and (2) each lattice site of the photonic crystals is still composed of closely contacted gold nanoparticles. Actually, these metallic photonic structures can be refurbished through a further annealing process. Using an annealing temperature above 450 °C, we have successfully removed the remaining photoresist and make the gold nanoparticles join into a solid homogenous unit on each lattice site after being fully molten. Thus, high-quality gold nanostructures with excellent plasmonic response can be obtained. This accomplished an improved recipe for the solution-processible fabrication of plasmonic nanostructures. The corresponding devices with improved optical properties become more suitable for biosensors and optoelectronic devices.     

Domain Purity,Miscibility, and Molecular Orientation at Donor/Acceptor Interfaces in High Performance Organic Solar Cells: Paths to Further Improvement

Domain purity and interface structure are known to be critical for fullerene‐based bulk heterojunction (BHJ) solar cells, yet have been very difficult to study. Using novel soft X‐ray tools, we delineate the importance of these parameters by comparing high performance cells based on a novel naphtha[1,2‐c:5,6‐c]bis[1,2,5]thiadiazole (NT) material to cells based on a 2,1,3‐benzothiadiazole (BT) analogue. BT‐based devices exhibit ～15 nm, mixed domains that differ in composition by at most 22%, causing substantial bimolecular recombination. In contrast, NT‐based devices have more pure domains that are >80 nm in size, yet the polymer‐rich phase still contains at least 22% fullerene. Power conversion efficiency >6% is achieved for NT devices despite a domain size much larger than the nominal exciton diffusion length due to a favourable trade‐off in the mixed domain between exciton harvesting, charge transport, and bimolecular recombination. The miscibility of the fullerene with the NT and BT polymer is measured and correlated to the purity in devices. Importantly, polarized x‐ray scattering reveals preferential face‐on orientation of the NT polymer relative to the PCBM‐rich domains. Such ordering has previously not been observed in fullerene‐based solar cells and is shown here to be possibly a controlling or contributing factor to high performance.     

Existing and Emerging Technologies for Point-of-Care Testing

The volume of point-of-care testing (PoCT) has steadily increased over the 40 or so years since its widespread introduction. That growth is likely to continue, driven by changes in healthcare delivery which are aimed at delivering less costly care closer to the patient’s home. In the developing world there is the challenge of more effective care for infectious diseases and PoCT may play a much greater role here in the future. PoCT technologies can be split into two categories, but in both, testing is generally performed by technologies first devised more than two decades ago. These technologies have undoubtedly been refined and improved to deliver easier-to-use devices with incremental improvements in analytical performance. Of the two major categories the first is small handheld devices, providing qualitative or quantitative determination of an increasing range of analytes. The dominant technologies here are glucose biosensor strips and lateral flow strips using immobilised antibodies to determine a range of parameters including cardiac markers and infectious pathogens. The second category of devices are larger, often bench-top devices which are essentially laboratory instruments which have been reduced in both size and complexity. These include critical care analysers and, more recently, small haematology and immunology analysers. New emerging devices include those that are utilising molecular techniques such as PCR to provide infectious disease testing in a sufficiently small device to be used at the point of care. This area is likely to grow with many devices being developed and likely to reach the commercial market in the next few years.