Post-Market Surveillance Assessment of the Clinical Accuracy of a Blood Glucose Monitoring System with an Improved Algorithm for Enhanced Product Performance.

BACKGROUND: On-going manufacturer-led post-market surveillance (PMS), assessing the clinical accuracy of blood glucose monitoring (BGM) systems, is critical to substantiate the performance of such products for people with diabetes. MATERIALS AND METHODS: Batches of Verio test-strip product were randomly and routinely selected over the period from launch of an improved-algorithm product to reporting date and sent to 3 clinic sites for clinician-led accuracy assessment. Accuracy is reported as per recently adopted FDA guidance for BGM systems, EN ISO 15197:2015 and MARD/MAD (Mean absolute relative difference/Mean absolute difference). RESULTS: Thirty-three individual test-strip batches were evaluated corresponding to 506 unique donors. Accuracy performance - FDA: 98.9% of values within ±15% of comparator; ISO: 99.0% within ±15 mg/dL or ±15% at <100 mg/dL (<5.55 mmol/L) or ≥100 mg/dL (≥5.55 mmol/L) glucose, respectively. Overall MARD was 4.19% with a MARD range of 3.54%-5.73% across all test strip batches. CONCLUSIONS: This post-market surveillance program demonstrates the new BGM system consistently meets measures of clinical accuracy specified by regulators. This program supports a growing demand by regulators for real-world evidence demonstrating consistent in-market product efficacy as opposed to the current largely passive approach that relies on assessment of reports filed by device users.

Development of a broad band AC power amplifier for real time turbulence feedback control experiment in the Saskatchewan Torus-modified (STOR-M) tokamak.

A gated oscillating power amplifier has been developed for high frequency biasing and real time turbulent feedback experiments in the Saskatchewan Torus-modified tokamak. This oscillator is capable of providing a peak to peak oscillating output voltage of around ±60 V with a current around 30 A within the frequency band 1 kHz-50 kHz without any distortions. The overall output power is amplified by a two-stage metal oxide semiconductor field-effect transistor power op-amp as well as nine identical push-pull amplifiers in the final stages. The power amplifier input signal, collected from the plasma floating potential during the tokamak discharge, is optically isolated from the tokamak vessel ground. The filtered floating potential fluctuations with a band width of 5 kHz-40 kHz were amplified and fed to an electrode inserted into the plasma edge to study the response of the plasma turbulence. We observe that magnetic fluctuations are suppressed due to real time feedback of the floating potential.

WITHDRAWN: Ozone therapy for the treatment of dental caries.

BACKGROUND: Dental caries is a bacterially mediated disease characterised by demineralisation of the tooth surface, which may lead to cavitation, discomfort, pain and eventual tooth loss. Ozone is toxic to certain bacteria in vitro and it has been suggested that delivering ozone into a carious lesion might reduce the number of cariogenic bacteria. This possibly could arrest the progress of the lesion and may, in the presence of fluoride, perhaps allow remineralisation to occur. This may in turn delay or prevent the need for traditional dental conservation by 'drilling and filling'. OBJECTIVES: To assess whether ozone is effective in arresting or reversing the progression of dental caries. SEARCH METHODS: We searched the Cochrane Oral Health Group's Trials Register (to 7 November 2003); Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2003, Issue 3); MEDLINE and PREMEDLINE (OVID) (1966 to November 2003); EMBASE (OVID) (1980 to November 2003); CINAHL (OVID) (1982 to November 2003); AMED (OVID) (1985 to November 2003). Quintessence was handsearched through 2002 and KaVo were contacted as manufacturers of the HealOzone apparatus for any additional published or unpublished trials. SELECTION CRITERIA: Inclusion was assessed independently by at least two reviewers. Trials were only included if they met the following criteria: randomisation in a controlled trial; single surface in vivo carious lesion accessible to ozone application; clear allocation concealment; ozone application to the lesions in the intervention group; no such application of ozone in the control group; outcomes measured after at least 6 months. DATA COLLECTION AND ANALYSIS: Reviewers independently extracted information in duplicate. A paucity of comparable data did not allow meta-analytic pooling of the included studies. MAIN RESULTS: Three trials were included, with a combined total of 432 randomised lesions (137 participants). Forty-two conference papers, abstracts and posters were excluded (from an unknown number of studies). The risk of bias in all studies appeared high. The analyses of all three studies were conducted at the level of the lesion, which is not independent of the person, for this reason pooling of data was not appropriate or attempted. Individual studies showed inconsistent effects of ozone on caries, across different measures of caries progression or regression. Few secondary outcomes were reported, but one trial reported an absence of adverse events. AUTHORS' CONCLUSIONS: Given the high risk of bias in the available studies and lack of consistency between different outcome measures, there is no reliable evidence that application of ozone gas to the surface of decayed teeth stops or reverses the decay process. There is a fundamental need for more evidence of appropriate rigour and quality before the use of ozone can be accepted into mainstream primary dental care or can be considered a viable alternative to current methods for the management and treatment of dental caries.

Evaluation of the performance of the OneTouch Select Plus blood glucose test system against ISO 15197:2013.

OBJECTIVES: Assess laboratory and in-clinic performance of the OneTouch Select(®) Plus test system against ISO 15197:2013 standard for measurement of blood glucose. METHODS: System performance assessed in laboratory against key patient, environmental and pharmacologic factors. User performance was assessed in clinic by system-naïve lay-users. Healthcare professionals assessed system accuracy on diabetes subjects in clinic. RESULTS: The system demonstrated high levels of performance, meeting ISO 15197:2013 requirements in laboratory testing (precision, linearity, hematocrit, temperature, humidity and altitude). System performance was tested against 28 interferents, with an adverse interfering effect only being recorded for pralidoxime iodide. Clinic user performance results fulfilled ISO 15197:2013 accuracy criteria. Subjects agreed that the color range indicator clearly showed if they were low, in-range or high and helped them better understand glucose results. CONCLUSION: The system evaluated is accurate and meets all ISO 15197:2013 requirements as per the tests described. The color range indicator helped subjects understand glucose results and supports patients in following healthcare professional recommendations on glucose targets.

Real-time monitoring of moisture levels in wound dressings in vitro: an experimental study.

Retaining an appropriate level of moisture at the interface between a healing wound and an applied dressing is considered to be critical for effective wound healing. Failure to control exudate at this interface can result in maceration or drying out of the wound surface. The ability to control moisture balance at the wound interface is therefore a key aspect of wound dressing performance. To date it has not been possible to monitor in any effective manner the distribution of moisture within dressings or how this varies with time. A new measurement system is presented based on sensors placed at the wound/dressing interface which are capable of monitoring moisture levels in real time. The system comprises a model wound bed and sensor array complete with fluid injection path to mimic exudate flow. Eight monitoring points, situated beneath the test dressing, allow the moisture profile across the complete dressing to be measured both during and after fluid injection. The system has been used to evaluate the performance of four foam dressings, a composite hydrofibre dressing and a film dressing. Stark contrasts in the performance of the wound contact layer were found between the different wound dressing types. The composite hydrofibre dressing retained moisture at the wound interface throughout the experiments while areas of the foam dressing quickly became dry, even during constant injection of fluid. The abundance of sensors allowed a moisture map of the surface of the wound dressing to be constructed, illustrating that the moisture profile was not uniform across several of the dressings tested during absorption and evaporation of liquid. These results raise questions as to how the dressings behave on a wound in vivo and indicate the need for a similar clinical monitoring system for tracking wound moisture levels.