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Background: In most patients having noncardiac surgery, blood pressure is measured with the oscillometric upper arm cuff method. Although the method is noninvasive and practical, it is known to overestimate intraarterial pressure in hypotension and to underestimate it in hypertension. A high-fidelity upper arm cuff incorporating a hydraulic sensor pad was recently developed. The aim of the present study was to investigate whether noninvasive blood pressure measurements with the new high-fidelity cuff correspond to invasive measurements with a femoral artery catheter, especially at low blood pressure.Methods: Simultaneous measurements of blood pressure recorded from a femoral arterial catheter and from the high-fidelity upper arm cuff were compared in 110 patients having major abdominal surgery or neurosurgery.Results: 550 pairs of blood pressure measurements (5 pairs per patient) were considered for analysis. For mean arterial pressure measurements, the average bias was 0 mmHg, and the precision was 3 mmHg. The Pearson correlation coefficient was 0.96 (P < 0.0001; 95% CI, 0.96 to 0.97), and the percentage error was 9%. Error grid analysis showed that the proportions of mean arterial pressure measurements done with the high-fidelity cuff method were 98.4% in zone A (no risk), 1.6% in zone B (low risk) and 0% in zones C, D, and E (moderate, significant, and dangerous risk, respectively). The high-fidelity cuff method detected mean arterial pressure values less than 65 mmHg with a sensitivity of 84% (95% CI, 74 to 92%) and a specificity of 97% (95% CI, 95% to 98%). To detect changes in mean arterial pressure of more than 5 mmHg, the concordance rate between the two methods was 99.7%. Comparable accuracy and precision were observed for systolic and diastolic blood pressure measurements.Conclusions: The new high-fidelity upper arm cuff method met the current international standards in terms of accuracy and precision. It was also very accurate to track changes in blood pressure and reliably detect severe hypotension during noncardiac surgery.Editor’s Perspective: [ABSTRACT FROM AUTHOR]

This article describes the development and deployment of Physics Toolbox Play, a gamified component of the Android Physics Toolbox Sensor Suite app, that can introduce young children through adults to fundamental physics principles. The app was used successfully in a variety of contexts, including STEM fairs with primary and secondary students and workshops with undergraduate physics majors and practicing teachers. Anecdotes from our experiences suggest that smartphones are an effective way to introduce learners to the big ideas and big principles in physics. [ABSTRACT FROM AUTHOR]

The article offers information on several physics equipment including the HDAWG arbitrary waveform generator from Zurich Instruments AG; XL4 high- performance linear amplifier from Aerotech Inc.; and FlexPDE Multiphysics software from PDE Solutions.

Reservoir pressure parameters [eg, reservoir pressure (RP) and excess pressure (XSP)] are biomarkers derived from blood pressure (BP) waveforms that have been shown to predict cardiovascular events independent of conventional cardiovascular risk markers. However, whether RP and XSP can be derived non-invasively from operator-independent cuff device measured brachial or central BP waveforms has never been examined. This study sought to achieve this by comparison of cuff reservoir pressure parameters with intra-aortic reservoir pressure parameters. 162 participants (aged 61 ± 10 years, 72% male) undergoing coronary angiography had the simultaneous measurement of cuff BP waveforms (via SphygmoCor XCEL, AtCor Medical) and intra-aortic BP waveforms (via fluid-filled catheter). RP and XSP derived from cuff acquired brachial and central BP waveforms were compared with intra-aortic measures. Concordance between brachial-cuff and intra-aortic measurement was moderate-to-good for RP peak (36 ± 11 vs 48 ± 14 mm Hg, P < 0.001; ICC 0.77, 95% CI: 0.71-0.82), and poor-to-moderate for XSP peak (28 ± 10 vs 24 ± 9 mm Hg, P < 0.001; ICC 0.49, 95% CI: 0.35-0.60). Concordance between central-cuff and intra-aortic measurement was moderate-to-good for RP peak (35 ± 9 vs 46 ± 14 mm Hg, P < 0.001; ICC 0.77, 95% CI: 0.70-0.82), but poor for XSP peak (12 ± 3 vs 24 ± 9 mm Hg, P < 0.001; ICC 0.12, 95% CI: -0.13 to 0.31). In conclusion, both brachial-cuff and central-cuff methods can reasonably estimate intra-aortic RP, whereas XSP can only be acceptably derived from brachial-cuff BP waveforms. This should enable widespread application to determine the clinical significance, but there is significant room for refinement of the method. [ABSTRACT FROM AUTHOR]

Exercise periodic breathing (EPB) is associated with exercise intolerance and poor prognosis in patients with heart failure (HF). However, EPB detection during cardiopulmonary exercise test (CPET) is difficult. The present study investigated the use of a wireless monitoring device to record the EPB during CPET and proposed quantization parameter estimates for the EPB. A total of 445 patients with HF were enrolled and underwent exercise tests. The ventilation data from the wearable device were compared with the data obtained during the CPET and were analyzed based on professional opinion and on 2 automated programs (decision tree [DT] and oscillatory pattern methods). The measurement accuracy was greater with the DT method (89 %) than with the oscillatory pattern method (75 %). The cutoffs for EPB recognition using the DT method were (1) an intercept of the regression line passing through the minute ventilation rate vs. the time curve during the recovery phase ≥64.63, and (2) an oscillatory phase duration to total exercise time ratio ≥0.5828. The wearable device was suitable for the assessment of EPB in patients with HF, and our new automated analysis system using the DT method effectively identified the EPB pattern. [ABSTRACT FROM AUTHOR]

The aim of the study was to analyze whether auscultatory normative values (Fourth Task Force [4TF]) can be applied to blood pressure (BP) obtained by oscillometric devices. The authors performed a retrospective analysis of oscillometric office BP and ambulatory BP monitoring in 229 children (116 boys), median age 15.31 years. Office systolic BP (SBP) and diastolic BP (DBP) values were converted into Z scores using 4TF and oscillometric (German Health Interview and Examination Survey for Children and Adolescent [KiGGS]) reference values. There was good correlation between the two normative methods (r=0.9773 for SBP, r=0.9627 for DBP). Results from Bland-Altman test revealed only minimal differences in Z scores between 4TF and KiGGS for SBP, but a significant proportional error for DBP. 4TF and KiGGS Z scores were equally predictive of ambulatory hypertension. In conclusion, auscultatory and oscillometric normative data are interchangeable for SBP but not for DBP. [ABSTRACT FROM AUTHOR]

The measurement of blood pressure in the office (OBP) remains the basis for hypertension diagnosis and management for more than half a century. Despite the increasing use of out-of-office blood pressure measurement using home and less so ambulatory monitoring and their endorsement by hypertension societies, at present and for some time to come it is likely that in many people the diagnosis and management of hypertension will be based on OBP measurement alone. OBP measurement is a very variable method affected by multiple factors, which have major impact on the OBP level, reproducibility and prognostic ability. Thus, there are several types of OBP measurement, depending on the device type, conditions, observer's presence and the number of readings. The 4 main OBP types are: Type I: Auscultatory OBP in clinical practice; Type II: Automated attended OBP in clinical practice; Type III: Research setting OBP; Type IV: Unattended automated OBP. These OBP types have different standardization level, different reproducibility, different clinical relevance and different thresholds for hypertension diagnosis. Unless the methodological details of OBP measurement are reported, any conclusions based on such measurements in clinical research and in practice are questionable. [ABSTRACT FROM AUTHOR]

In this paper, we present experimental saturation curves of a small gap miniature fission chamber obtained in the MINERVE reactor. The chamber is filled with argon at various pressures, and the fissile material can be coated on the anode, cathode, or both. For analyzing the recombination regime, we consider a model of columnar recombination and discuss its applicability to our chamber. By applying this model to the data, it is possible to estimate the ratio between the recombination coefficient k and an effective column radius b , appearing in the model, to be k / b = ( 2.5 ± 0.9 ) × 10 − 6 m 2 / s for argon. From these results, a routine measurement of the recombination regime is proposed in order to detect gas leakage. This online diagnosis would be beneficial in terms of lifetime and reliability of the neutron instrumentation of nuclear reactors. [ABSTRACT FROM AUTHOR]

The article evaluates several physics equipment including the VCP Pirani vacuum transducer from Thyracont Vacuum Instruments GmbH, the scanning ion-conductance microscopy (SICM) module from Park Systems Inc., and the X-Max Extreme silicon drift detector from Oxford Instruments Plc.

We have designed and built a fast and precise balanced polarimeter from components commonly found in undergraduate physics laboratories. Balanced polarimetry measures the orientation of linearly polarized light by splitting the beam into orthogonal polarization components and detecting each separately. Our polarimeter is capable of measuring the orientation of linearly polarized light with a precision of approximately 0:001°√Hz. The apparatus cost less than $1000. Measurements of the specific rotation of sucrose and of the Faraday effect were performed, both of which produced results that were comparable to previously reported values. [ABSTRACT FROM AUTHOR]

The article offers information on several physics equipment including Nexis GC-2030 gas chromatograph from Shimadzu Scientific Instruments Inc.; Cold-cathode vacuum transducer from Thyracont Vacuum Instruments GmbH and Electron diffraction detector from Oxford Instruments Plc.

Objectives: To monitor the influence of the power density of the curing unit on the setting behaviour of light-cured glass-ionomer cements (LCGICs) using ultrasound measurements.Methods: The ultrasound equipment comprised a pulser-receiver, transducers and an oscilloscope. The LCGICs used were Fuji II LC, Fuji II LC EM and Fuji Filling LC. The cements were mixed according to the manufacturer's instructions and then inserted into a transparent mould. The specimens were placed on the sample stage and cured with power densities of 0 (no irradiation), 200 or 600 mW/cm(2). The transit time through the cement disk was divided by the specimen thickness and then the longitudinal ultrasound velocity (V) within the material was obtained. Analysis of variance and Tukey's Honestly Significantly Different test were used to compare the V values between the set cements.Results: When the LCGICs were light-irradiated, each curve displayed an initial plateau at approximately 1500 m/s and then rapidly increased to a second plateau at approximately 2600 m/s. The rate of increase of V was retarded when the cements were light-irradiated with a power density of 200 mW/cm(2) than with a power density of 600 mW/cm(2). Although sonic echoes were detected from the beginning of the measurements, the rates of increase of the sonic velocity were relatively slow when the cement was not light-irradiated.Conclusions: The ultrasound device monitored the setting processes of LCGICs accurately based on the longitudinal V. The polymerization behaviour of LCGICs was shown to be affected by the power density of the curing unit. [ABSTRACT FROM AUTHOR]

The article reviews commercial products related to physics, including the model 565 digital pulse and delay generator from Berkeley Nucleonics Corp., the CNT-90XL line of microwave frequency counters and analyzers from Pendulum Instruments, and the model 2810 vector signal analyzer from Keithley Instruments.

Provides information on several products relevant to physics. S9132 profile sensor from Hamamatsu Corp.; Electrooptic modulator driver from New Focus; Digital IR camera from Indigo Systems.

Presents detailed instructions for the construction of a pyramidal laser cooling and trapping apparatus. Laser stabilization and tuning; Diagram of optical layout of pyramidal trap; Image of laser-cooled atomic cloud.

Objectives. Scanning laser vibrometry is a non-invasive method of accurately measuring the vibratory characteristics of oscillating objects. The aim of this study was to observe, using a scanning laser vibrometer (SLV), the vibration patterns of dental ultrasonic scaler tips and to assess the effects of water flow rate and power setting on these patterns whilst operating the tips in an unloaded environment.Methods. A 30 kHz ultrasonic scaler (TFI-10, Dentsply) was fixed in position and a laser beam from the SLV was focused onto the tip. The laser, guided by a virtual measurement grid, was scanned over the oscillating tip surface. Scans were taken with the laser beam perpendicular to the long axis of the front face of the tip.Results. Oscillation frequencies and the displacement amplitude at the unconstrained end of the tip were measured for various power/water settings. Vibration nodal positions were recorded for the various settings and were found to occur approximately 4 mm from the free end of the tip. At low and medium power settings, tip displacement amplitude was reduced by increased water flow. At high power settings, combined with a high flow rate, the water leaves the body of the instrument as a jet. This left the tip relatively unconstrained, allowing it to oscillate at increased displacement amplitudes.Conclusions. This study shows that the SLV is able to accurately characterise the movement of oscillating ultrasonic scaler tips. The tips are affected by power setting and water flow rates. [Copyright &y& Elsevier]

Background: Voluntary muscle strength declines significantly in older adults. One contributing factor to the strength loss is muscle atrophy developed in old age. Whether the ability to maximally activate the muscle decreases with age, however, is unknown. This study was intended to determine if the central nervous system command to maximally activate the biceps brachii muscle deteriorates with age.Methods: Electrical stimulation pulses were applied to the skin overlying the biceps brachii muscle during maximal voluntary elbow-flexion contractions. The magnitude of force evoked on the maximal voluntary force was measured to determine the activation level (AL) of the muscle.Results: The AL was 94% for the elderly group and 97% for the young group (100% AL indicates complete activation). The AL for both the elderly and young groups was significantly (p<.05) lower than 100%. The AL of the elderly group was significantly (p<.05) lower than that of the young group.Conclusions: The loss of voluntary strength in older adults is a mixed result of muscle atrophy and a reduced ability to fully activate muscle. [ABSTRACT FROM AUTHOR]

Presents information on galvanoscopes, instruments which are used to measure the passage of an electrical current. Who devised the instrument; Description of the galvanoscopes; History on the instrument.

Lists the products in the Buyer's Guide of the periodical 'Physics Today.' Accelerators; Accelerometers; Acoustical apparatus; Acoustical calibrators; Electrically conductive adhesives; Heat-resistant alloys; Alpha spectrometers; Air filters; High-temperature adhesives; Electric motor controllers; Electromagnets; Digitizers; Discriminators.

Lists the suppliers in the Buyer's Guide of the periodical 'Physics Today.' AAK Corp.; Ace Glass Inc.; Acton Research Corp.; Columbia Scientific Industries; Consolidated Controls Corp.; Laser Lines Ltd.; Laser Photonics Inc.; LECO Corp; Laser Power Corp.; SPEX Industries Inc.; Star Systems; Supelco Inc.

Lists the products in the Buyer's Guide of the periodical 'Physics Today.' Accelerators; Water-cooled baffles; CAMAC branch highway cables; Data acquisition; Crystal ovens; Hazardous gas detectors; Diamond drills; Diamond saws; Electric heating tape; Gallium arsenide.

Reports on the construction of the Stanford Linear Collider (SLC) as of September 1984. How the SLC is the crucial testing ground of a new accelerator technology that is seen as crucial if electron-positron collision energies are pushed much beyond what Large Electron Positron storage ring (LEP) will make available; How LEP is under construction near Geneva; Linear colliders. INSETS: Fusion experiments have begun at Antares;Nova nears completion.

Focuses on the increasing demand for micro electrical mechanical systems (MEMS) in the United States. Industrial and commercial applications of MEMS; Characteristic of the device; Emergence of the market for MEMS design software.

Presents an alphabetical listing of product entries related to physics. Includes baffles; Beam scanners and deflectors; Cables; Accelerators; Amplifiers; Anemometers; Anvils; Atomic fluorescence spectrometers; Educational apparatus.

The article discusses the possibility of undiscovered long-lived particles created by the Large Hadron Collider (LHC). Topics include the design of the Compact Muon Solenoid (CMS) and the A Toroidal LHC Apparatus (ATLAS) particle detectors, the creation of the Forward Search Experiment (FASER) tracker in relation to the work of theorist Jonathan Feng, and the costs of possible detectors to be constructed.

The article offers brief information on several equipment and materials related to physics including the MasterSil 156 from Master Bond Inc., the ADPC 302 in-process management system from Pfeiffer Vacuum GmbH, and the 821HH ultrahigh impedance voltmeter technology from Trek Inc.

The article previews physics instruments and equipment, including 1290 and 1260 Infinity evaporative light scattering detectors from Agilent Technologies, nanomechanics package for bio-atomic force microscopy from Bruker and programmable digital stirring hot plates from Torrey Pines Scientific.

The article offers brief information on several products for use in physics including the Agilent 6420 triple quadrupole liquid chromatography-mass spectrometry (LC/MS) system from Agilent Technologies Inc., the Hiden QGA mass spectrometer from Hiden Analytical Inc., and the Omega Engineering PXM309 Metric series from Omega Engineering Inc.

The article reviews several computer softwares, and equipments and supplies related to physics including the peripheral component interconnect express (PCle) high-speed digitizer from the company Agilent Technologies, the xDAP 7400 data acquisition option for personal computer (PC) systems from Microstar Laboratories Inc., and the LightTools 6.3 illumination design and analysis software from the company Optical Research Associates.

Lists physics related instruments and tools including precision barometers.

The article offers brief information on several physics equipment and supplies including the i-Speed 508 camera from iX Cameras, the 871B-NIR2 infrared (IR) laser wavelength meter from Bristol Instruments Inc., and the WaveEye wavelength-measuring device from Laser Components USA Inc.

Features various materials and components for applied physics. Effect of information load on bandwidth increase in optical fiber communication systems; Use of electromagnetic acoustic transducer to monitor microstructural changes in steel; Introduction of softwares for image processing and thermal analysis.

Features various scientific instruments for applied physics. Presentation of spectrometer systems for spectral analysis; Improvements in software spectrophotometer for repetitive testing research; Modification of laser design for improved applicability.

Features several products for the field of applied physics. Specifications of the microprocessor-controlled torque rheometer from Haake Buchler Instruments; Capabilities of the diffracting grating and monochromator from The Optometrics Group; Availability of ultraclean vacuum ovens with infrared heaters from Elnik Systems.

Features several equipments and supplies in physics in the U.S. Capability of the molecular-drag vacuum pump from Alcatel Vacuum Products; Specification of the micropositioning piezoelectric translators from Polytec Optronics; Introduction of a color-and energy-stabilized light pulser from Berkely Nucleonics.

Evaluates several scientific equipments applied in physics. Video camera by Photonic Microscopy Inc.; High-voltage power supplies from the Dutch firm High Voltage Engineering Europa; Photodiode mount and streak camera tubes from Instrument Technology Ltd..

Evaluates several commercial products on physics in the United States. Performance of the HA100 hemispherical analyzer from VSW Scientific Instruments; Features of the FTS 4060 cesium time and frequency standards from Frequency and Time Systems; Price of the digital oscilloscope peripheral from Rapid Systems.

Presents product review briefs. High-voltage power supplies with digital monitoring from Bertan Associations; Rotary feedthroughs for vacuum chambers by Shrader Scientific; Digital delay generator with wide timing range by Stanford Research Systems; Other product review briefs.

Features several products for the field of physics. Specifications of the capacitor-charging pulsed power supply from A.L.E. Systems; Capabilities of the programmable voltmeter with 16-bit resolution from Keithley; Availability of the quadruple mas spectrometer from Balzers.

Presents several scaling products use in physics. FM-1 mode scrambler of Newport; Spectrodiameter by Bentham; Line Drive 3000 software and hardware package from Light Machines.

Features several products on physics. Introduction of piezoelectric motors by Burleigh Instruments; Features of logic modules for CAMAC and FAST BUS systems by Nova; Ability of silicon spectrometers in stopping high energy protons and charged particles introduced by EG&G Ortec.

Features several products related to physics. Distribution of a C-language scientific library from Peerless Engineering Service; Capabilities of 9400 dual 125-MHz digital oscilloscope from LeCroy; Details of AV-107 pulsed constant-current generators from Avtech.

Presents several physics-related products. Accuracy of the precision resistance thermometer from Minco Co.; Applications of the radiation survey meter to medical physics from Victoreen Co.; Specifications of the Bayard-Alpert hot filament ionization gauge from Varian Associates Inc.; Dimensions of superconducting magnets from Nicolet Analytical Instruments.

Presents descriptions of new products related to physics. Waveform digitizer which operates at 200 megasamples per second; Polychromator for Thomson-scattering spectral analysis; Sample-and hold amplifier with nanosecond aperture.

Describes several products related to physics as of February 1983. Model 2100 Dyescan laser from EG&G Princeton Applied Research; C1370 streak camera from Hamamatsu; Monospec 50 spectrometer from Jarrel-Asb.

Introduces several equipment and materials for physics research. Microscan 9 scanning electron beam microanalyzer from Cambridge Instrument Co. Inc.; Cube beamsplitters from Melles Griot; 751 atomic absorption spectrophotometer from Instrumentation Laboratory Inc.; 4800 series continuous dynode electron multiplier from Educational Calculator Devices Inc.

Introduces several instruments and materials for physics. Holographic camera from Spectrum Development Corp.; 8000 computer interface system from Beckman Instruments Inc.; Sequentorr digital controller for vacuum pumping stations from Technology Corp.