Accurate Time Measurements Research Articles

Accuracy of warm ischemia time measurement using a surgical intelligence software in partial nephrectomies: A validation study

AbstractObjectivesThe objectives of this study are to compare the accuracy of warm ischemia times (WITs) derived by a surgical artificial intelligence (AI) software to those documented in surgeon operative reports during partial nephrectomy procedures and to assess the potential of this technology in evaluating postoperative renal function.Patients and methodsA surgical AI software (Theator Inc., Palo Alto, CA) was used to capture and analyse videos of partial nephrectomies performed between October 2023 and April 2024. The platform utilized computer vision algorithms to detect clamp placement and removal, enabling precise WIT measurement. Expert‐reviewed surgical videos served as the ground truth. Platform‐derived WITs were compared to those in surgeon operative reports using paired‐sample t‐tests. Additionally, we analysed the correlation between platform‐derived WITs and postoperative creatinine levels extracted from electronic health records (EHRs) integrated via health level seven (HL7) messaging protocols.ResultsOf 64 eligible cases, 61 were included in the final analysis. Platform‐derived WITs were within 1 min of the ground truth in all procedures, within 30 s in 97%, and within 10 s in over 80%. The mean difference between platform‐derived WITs and ground truth was 8.3 s, significantly lower than the 2.45 min difference for operative reports (p < 0.001). No significant correlation was found between platform‐derived WIT and postoperative creatinine changes, aligning with the view that WIT may not independently determine postoperative renal function. Although not the primary goal of this study, significant correlations were observed between WIT, tumour size and RENAL score.ConclusionThis study demonstrates the high accuracy of a surgical intelligence platform in measuring WIT during partial nephrectomies. The findings support the use of AI‐based surgical time measurement for precise intraoperative documentation and highlight the potential of integrating these data with EHRs to advance research on surgical outcomes.

Intensity- and time-based strategies for micro/nano-sizing via single-particle ICP-mass spectrometry: A comparative assessment using Au and SiO2 as model particles

BackgroundSingle-particle ICP-mass spectrometry (SP-ICP-MS) is a powerful method for micro/nano-particle (MNP) sizing. Despite the outstanding evolution of the technique in the last decade, most studies still rely on traditional approaches based on (1) the use of integrated intensity as the analytical signal and (2) the calculation of the transport efficiency (TE). However, the increasing availability of MNP standards and advancements in hardware and software have unveiled new venues for MNP sizing, including TE-independent and time-based approaches. This work systematically examines these different methodologies to identify and summarize their strengths and weaknesses, thus helping to determine their preferred application areas. ResultsDifferent SP-ICP-MS methods for MNP sizing were assessed using AuNPs (20–70 nm) and SiO2MNPs (100–1000 nm). Among TE-dependent approaches, the particle frequency method was characterized by larger uncertainties than the particle size method. The results of the latter were dependent on the appropriate selection of the reference MNP, making the use of multiple reference MNPs recommended. TE-independent methods were based on external (linear and polynomial) calibrations and a relative approach. These methods exhibited the lowest uncertainties of all the strategies evaluated. External calibrations benefited from simpler calculations, but their application could be hindered by a lack of reference MNPs within the desired size range or by the need for interpolations outside the calibration range. Finally, transit time signals are directly proportional to the MNP size rather than its mass. The time-based method demonstrated adequate performance for sizing AuNPs but failed when sizing the largest SiO2MNPs (1000 nm). Significance and noveltyThis work provides further insights into the application of different SP-ICP-MS methodologies for MNP sizing. Both TE-independent approaches and the monitoring of the transit time as the analytical signal are underused strategies; in this context, a Python script was developed for accurate transit time measurement. After 20 years of development, a quantitative comparison of the different methodologies, including the most novel approaches, is deemed necessary for further growth on solid theoretical ground.

Photon number adaptive single-photon detection with time-walk passive compensation.

In long-distance laser time transfer, such as satellite-to-satellite and satellite-to-ground, the accuracy of flight time measurement for photon pulses is significantly compromised by the time walk phenomenon, stemming from variations of the incident photon numbers. In this paper, we propose a single-photon detection method, which is adaptive to the photon number, and passively compensates for the time walk effect. This method utilizes a fiber ring to divide an incident photon pulse into a series of photon pulse trains, with each pulse in the train separated by equal time intervals and subject to equal attenuation. The last detected photon pulse in the pulse train can always be attenuated to a single-photon level sufficient to render the time walk effect negligible. The experimental results demonstrate that the proposed method effectively mitigates the time walk effect across a range of average photon numbers, spanning from 1 to 100. It provides high-precision single-photon detection for laser time transfer in complex and variable environments.

Decoding microwave modulation transfer: The impact of dissipation through stochastic processes

AbstractAn anomalous transfer of modulation from a modulated microwave beam () to an unmodulated one () has been experimentally demonstrated through accurate delay time measurements. These results are analyzed according to two possible interpretations: one based on an electromagnetic approach as reported elsewhere, and the other based on a purely stochastic model. This latter model, made up of random zig‐zag paths, is the focus of the current paper. It is demonstrated that it is possible to obtain a plausible description of the experimental data.

Early Renaissance Concepts of Time and the Invention of Mechanical Clocks

Mechanical clocks appeared in Europe at the end of the thirteenth century and became widespread during the fourteenth century. Clocks utilized a periodic process – the oscillation of a verge – for accurate time measurement, which is consistent with the Aristotelian concept of time defined by motion. The concept was at the center of debates among scholastics and theologians, which culminated in the Church's Condemnation of Aristotelian teaching in 1277. The debate also led to the discovery of Impetus (inertial motion) by Buridan and Oresme. Sand clocks became a popular device at about the same time. The pendulum clocks invented by Huygens in the 1650s utilized linear oscillations, which, unlike the earlier verge mechanism, had their natural frequency. Both mechanisms are analyzed to explain why the introduction of the linear oscillator led to a 30-times accuracy improvement of the clock.

Accuracy of Reaction Time Measurement on Automated Neuropsychological Assessment Metric UltraMobile.

This observational study examined the accuracy of simple reaction time (RT) measurements on various touchscreen tablet devices using the Automated Neuropsychological Assessment Metric (ANAM) UltraMobile test battery. The study investigated the implications of interpreting ANAM UltraMobile with laptop-based normative data by analyzing the magnitude and variability of RT accuracy across devices. RT accuracy on 10 different tablets was assessed using a photodetector and robotic arm to respond to stimuli at predetermined response times. The recorded RT was compared with the true RT obtained from the robotic arm to calculate the RT error. ANAM UltraMobile recorded slower RTs than the laptop version. Additionally, RT error varied considerably among the 10 tablet models, suggesting psychometrically significant implications that could lead to interpretive errors when using laptop-based normative data. Relative to the RT error from the laptop-based version of ANAM, tablet data from ANAM UltraMobile are significantly slower and exhibit large variability between devices. These differences may have clinically significant implications for the comparability of the two versions. The findings suggest that further research with human participants is needed to assess the equivalence of ANAM UltraMobile with its predecessor.

Top-Down Design Method of a Time Domain Accelerometer with Adjustable Resolution.

A top-down design methodology and implementation of a time domain sensor is presented in this paper. The acceleration resolution of the time domain sensor is equal to the time-measurement accuracy divided by the sensor sensitivity. Combined with the sensitivity formula, the acceleration resolution is proportional to the vibration amplitude, the time-measurement accuracy, and the third power of the resonant frequency. According to the available time-measurement accuracy and the desired acceleration resolution, the parameters including the vibration amplitude and the resonant frequency were theoretically calculated. The geometrical configuration of the time domain sensor device was designed based on the calculated parameters. Then, the designed device was fabricated based on a standard silicon-on-insulator process and a matched interface circuit was developed for the fabricated device. Experimental results demonstrated that the design methodology is effective and feasible. Moreover, the implemented sensor works well. In addition, the acceleration resolution can be tuned by adjusting the time-measurement accuracy and the vibration amplitude. All the reported results of this work can be expanded to other time domain inertial sensors, e.g., a gyroscope or tilt sensor.

Thermoelectric generator powered timepiece circuit for rechargeable battery operation

The advent of digital technology has revolutionized the way we keep track of time. Digital watches have become an essential part of our daily lives and provide us with accurate and reliable time measurement. However, battery reliability is a long-standing issue in the digital watch industry. Batteries require frequent replacement and are a major source of waste. To solve this problem, a digital watch that runs on a lithium-polymer battery that is recharged by a voltage generated by a thermoelectric generator (TEG) placed on the hand. The proposed model uses TEG1-19913 that generates power in the range of 11.5 W to 14.5 W with hot end basking at 250 °C and a cold end between 30 °C and 50 °C. The TEG voltage is used to charge the lithium polymer battery, eliminating the need for conventional charging methods. The watch is designed to be compact and lightweight, so it can be worn comfortably for extended periods of time. The TEG is integrated into the watch strap and ensures that it is constantly in contact with the skin. The lithium-polymer battery used in the watch is a high-performance rechargeable battery that has high energy density and long life. In summary, the proposed digital watch is an innovative ecological solution to the problems associated with traditional battery-powered watches. The compact and light design of the watch combined with the energy-efficient display makes it a convenient and efficient timekeeping device.

Comparison of timing discrimination method for pulse-based Lidar

Time discrimination methods of pulse signals serve as the foundation for ranging, identification, and precision in pulse Lidar. Therefore, employing a judicious time discrimination method is pivotal in enhancing Lidar overall performance. This study initially delves into the theoretical distinctions among various time discrimination methods, including constant fraction timing, waveform centroid, dual-threshold waveform, and amplitude with rising edge compensation timing. It meticulously analyzes and compares these diverse methods for time discrimination. Subsequently, employing these methodologies to process Lidar echo signals to contrast their time measurement accuracy. The conclusions will provide valuable guidance for the design and practical application of pulse-type Lidar systems.

Features of quantum measurement standards and special status of the second in the SI-2019

The implementation of the New SI in 2019 and the definition of base units in terms of “defining constants” has significantly changed the metrology methods and led to the introduction of a quantum approach to the reproduction of units. The paper highlights a number of features of quantum methods and measurement standards, the ultimate accuracy of which is limited only by the “quantum structure of nature”. For electrical measurements, the implementation of the New SI means the end of the dualism that has existed since 1990. The dualism was that the SI defined the ampere – base unit of electricity – by mechanical measurements and quantities, and for reference measurements in practice, it was recommended to use the quantum effects of Josephson and Hall.
 A number of features of quantum methods and measurement standards are considered, which made it possible to increase the accuracy of reproduction of electrical units (and even earlier – units of time and length) by several orders of magnitude compared to the “pre-quantum” era.
 Another feature of the SI-2019 was the fact that it linked the units of all base quantities to the second and thus paved the way for the reproduction of units in terms of defining constants (which are fixed without uncertainty in the SI-2019) and the second, which is measured with the highest accuracy. Thus, the main task of metrology is to establish the relationship between the measured value and the second. In electrical measurements and some other types of measurements, this function is performed by quantum methods, which are described in this paper.
 The extremely high accuracy of time measurements, the availability of its transfer via communication lines, and the system-forming nature of the second determine its special status in SI-2019.
 The paper presents that the success in creating frequency measurement standards in the optical range promises further improvement of the accuracy of the second, which only raises its status and may lead to official revision of its definition in terms of the frequency of another quantum transition already existing in the optical range.
 It is suggested that the development of quantum measurement methods, the counting nature of these methods, and the features of the second mentioned in the paper bring us closer to the creation of a new metrology that will be a logical continuation of quantum metrology and which can be conventionally called “digital”.

A monolithic active pixel sensor with node-based, data-driven, parallel readout for the high energy physics experiment vertex detector

We present the design of a prototype MAPS sensor MIC6_V1 based on a 55 nm Quad-well CMOS Image Sensor process for the CEPC vertex detector. A new node-based, data-driven, parallel readout architecture is implemented to achieve high spatial resolution, fast readout, and low power consumption. The size of MIC6_V1 is 2.8 mm × 2.8 mm, which contains a pixel matrix of 64 rows by 64 columns, and the pixel size is 23.6 μ m × 20 μ m. The integration time is 5 μs, and the hit arrival time measurement accuracy is 10 ns.

Automation of aquaponics systems through integration of RTC modules, turbidity sensors, and water level sensors

Automation of aquaponics systems is key in increasing agricultural efficiency and productivity. A system considered an innovative method of sustainable food production that combines fish farming with agriculture simultaneously. The problem that often occurs is crop failure, due to the lack of technology that can monitor automatically, so that farmers experience losses as a result of fish and plant growth does not thrive, and problems in urban areas that require land for planting and fish farming due to limited land in urban areas. There is another problem with the lack of accurate timing and monitoring of water quality in aquaponics. The purpose of this research is to implement an IoT system in aquaponics that is connected to various sensors, such as Turbidity sensors, Water Level sensors, and RTC Modules. To monitor water quality conditions in tilapia habitat and accurate time measurement to provide fish feed automatically so as to improve fish health and growth and support better and consistent yields. The findings of this study show that the implementation of IoT systems in aquaponics can overcome environmental monitoring and control problems effectively. Using the integration of RTC modules, turbidity sensors, and water level sensors effectively improves the automation of aquaponics systems. This optimized system provides better monitoring of environmental conditions, reduces reliance on manual maintenance, and increases overall productivity. It helps increase tilapia growth and plant productivity in a modern aquaponics system. This research demonstrates the great potential of IoT technology in increasing efficiency and productivity in aquaponics aquaculture, so that it can push the fisheries sector towards a more advanced and competitive direction. So the main conclusion is expected that this automation can increase the productivity of ecosystem balance, and can face food security challenges and move towards more environmentally friendly solutions, towards effective management in the future.

Unveiling the Potential of Mixed Reality: Enhancing Time Measurement and Operator Support in Manual Assembly Processes

This study investigates the potential of Mixed Reality (MR) in the manual assembly processes and conducts a case study at a pump manufacturing plant in Sweden. An MR solution is developed to assist operators through visual instructions and guiding aides. The solution also captures the operator's motions using advanced hand and eye tracking features for real-time guidance and accurate time measurement. The proposed MR solution uses the build feature of HoLolens and a workstation editor, which facilitates the use of the solution in diverse assembly environments. The results of the experiments show that the developed MR solution can improve operator support, reduce errors, and enhance the overall efficiency of manual assembly processes. Moreover, it is shown to be an efficient tool for time measurement of the manual assembly process that has promising potential to replace sophisticated and time-consuming traditional time study methods.

Sub-Nanosecond UTC Dissemination Based on BDS-3 PPP-B2b Service

The BeiDou-3 system (BDS-3) broadcasts PPP-B2b signals to provide real-time PPP service. Compared with the traditional PPP technique, the PPP-B2b service broadcasts corrections through satellite links, covers a wide area, and is independent of the internet. With the PPP-B2b service, users can obtain high-precision positioning information through the real-time PPP. Many studies have been conducted to evaluate the positioning performance of PPP-B2b. In theory, high-precision timing information could also be obtained through PPP-B2b. With the development of science and technology, the need for highly accurate time measurement, even at the sub-nanosecond level, is experiencing significant growth. However, the GNSS standard timing service can hardly meet these requirements. This contribution analyzes the timing performance of the PPP-B2b service and proposes a sub-nanosecond precise timing method of Coordinated Universal Time (UTC) based on the PPP-B2b service. BDS-3 and GPS observations from nine tracking stations and real-time collected PPP-B2b corrections over 516 days were used to analyze the performance of the proposed timing method. The results show that: (1) The difference between the PPP-B2b-restored UTC, which was realized by one-way timing with the UTC offsets in broadcast ephemeris, and UTC (NTSC), fluctuates within a few ns. (2) The timing uncertainty of the zero baseline based on the proposed method is better than 0.2 ns. (3) Compared with the post-processed PPP time transfer, the UTC dissemination uncertainty of the short and long baseline with the proposed method is better than 0.7 ns. The experiment results verified the feasibility of the proposed sub-nanosecond level precise UTC dissemination method based on the PPP-B2b service.

Time of Flight Measurement Method Combining Threshold Method and Cross-Correlation Method

With various benefits such as a large range ratio, suitability for large-diameter measurement, and lack of excess pressure drop, ultrasonic flowmeters (UFMs) have been widely adopted in natural gas measurement. The accuracy of flow measurement in transit-time UFMs is mostly dependent on the accurate measurement of time of flight (TOF). The threshold method, the cross-correlation (CC) method, and the model-based method are examples of traditional TOF calculation techniques. However, the threshold method is susceptible to such factors as waveform distortion, amplitude attenuation, and noise, the CC method is constrained by the sampling frequency, and the model-based method necessitates a significant investment in calculation time and resources. Based on the analysis of the shortcomings of traditional TOF measurement methods, a TOF measurement method that combines the threshold method and CC method is presented. This method integrates the advantages of the high measurement resolution of the threshold method and the strong robustness of the CC algorithm. The results demonstrate that the flow rate accuracy and the repeatability of the TOF are greatly improved by this method.

The state primary standard of units of time, frequency and the national time scale GET 1-2022: contribution to the formation of Coordinated Universal Time

Measurement of time and frequency is one of the most widespread types of measurements, information on the exact value of time, on the national time scale is extremely in demand by a wide variety of consumers, ranging from commercial electricity metering systems, where the required synchronization accuracy is a few seconds, to space navigation systems that impose requirements on synchronization at the level of units of nanoseconds. At the same time, consumer requirements for the accuracy of time and frequency measurements, as well as for the efficiency of obtaining time-frequency information, are steadily growing, which entails the need to modernize the means of reproducing, storing and transmitting units of time, frequency and time scale. To meet modern consumer requirements for the accuracy of time and frequency measurements, technical means of reproduction, storage and transmission of units have been introduced into the State primary standard of units of time, frequency and national time scale GET 1-2022, allowing to significantly increase the contribution of GET 1-2022 to the formation of the coordinated universal timescale UTC. A brief overview of the composition of GET 1-2022 is given, a comparative analysis of the contribution of time standards to the formation of the UTC timescale is carried out, as well as an analysis of the shifts of the time scales of the standards relative to UTC and the instability of the frequency standards. It is shown that from September 2022 to March 2023, the contribution of GET 1-2022 to the formation of the UTC increased significantly and exceeded that of the US Naval Observatory standard, and currently the contributions of these standards are comparable. In terms of frequency instability and average contribution to the formation of UTC, the atomic standards of GET 1-2022 are significantly superior to similar standard instruments from other countries. It has been established that the national coordinated time scale UTC(SU) is one of the best national implementations of UTC, and the national atomic time scale TA(SU) occupies a leading position among the time scales of leading foreign time laboratories in terms of instability.

Development of the scintillating fiber timing detector for the Mu3e experiment

We present the development and discuss the performance of a compact scintillating fiber detector for the Mu3e experiment for accurate time measurements at very high particle rates. Mu3e is a new experiment under preparation at the Paul Scherrer Institut (PSI) to search for charged Lepton Flavor Violation in the neutrinoless muon decay μ+→e+e−e+ with a projected sensitivity of 10−16 using the most intense continuous surface muon beam in the world. A very thin scintillating fiber detector (thickness <0.2% of a radiation length X0) with a time resolution of about 250 ps, efficiency around 97%, and spatial resolution of ∼100μm has been developed. The SciFi detector is read out with multi-channel silicon photomultiplier arrays at both ends to achieve the best timing performance. Different scintillating fiber types have been evaluated and various assembly procedures have been tested to achieve the best performance.

Ion detector of time-of-flight mass spectrometer with registration of leading and trailing edges.

The accuracy of the ion flight time measurement in the time-of-flight mass spectrometer is critical to achieving high resolution. The pulse amplitude variation of the detector pulses leads to the registration time spread at a given pulse detection threshold. This time spread can be eliminated by determining the position of the pulse apex. To determine the position of the pulse apex, the output of the ion detector is fed simultaneously to the two channels of the time-to-digital converter. In this case, the first channel is set to register the leading edge, and the second channel is set to register the trailing edge of the pulse. Using a simple processing of the received data, the position of the pulse tip is determined. Thus, the dependence of the temporal position of the peak on the pulse amplitude is largely eliminated. Examples are given, and the efficiency of using this algorithm to increase the resolution of time-of-flight mass spectral peak registration is demonstrated.

Real-time monitoring of the dissolution of pH-responsive polymer coatings by capacitive sensing with signal protection mechanism

Accurate assessment of pH-responsive polymer dissolution in vitro is crucial for formula design in drug delivery systems. This study developed a high-performance capacitive sensing system (Cap-S) with a screen-printed carbon electrode (SPCE) for real-time monitoring and evaluating the dissolution rate of EUDRAGIT® FL 30 D-55 and L 30 D-55 polymers. The linear detection range of the Cap-S is 1.000–4.000 pF (R2 = 0.9909) with a sensitivity (0.309 fF/fF). The sensor system exhibited a tri-phasic response with a dual-sigmoidal curve, allowing for accurate measurement of the dissolution time of polymers to reach 50 % capacitance shift (T50 %). The Cap-S showed outstanding temporal resolution (0.1 s) in monitoring polymer dissolution without the need for an electroactive probe commonly used in electrochemistries. It also provides a realistic and discriminative in vitro dissolution assessment of enteric-coated formulations in Hanks' buffer (T50 % = 409 s and > 5.6 h to FL 30 D-55 and L 30 D-55, respectively) versus Sorensen's phosphate-buffered saline (T50 % = 532 s and =1761 s to FL 30 D-55 and L 30 D-55, respectively), among others. The approach is a compact and precise method for real-time monitoring and quantitative assessment of polymer dissolution.

Optimization of the Parameters of the Magnetizing Device of the Electromagnetic-Acoustic Transducer

Contactless electromagnetic-acoustic transducers have a set of significant advantages over contact transducers, but at the same time they have significant disadvantages that require the development of effective magnetizing devices. Compared to magnetizing devices that are using permanent magnets, electric current magnetization devices are easily removed from the object of testing and cleaned from contamination by metal particles. Unfortunately, such transducers have significant dimensions and weight.A transducer containing a magnetic circuit magnetized by an electric current coil and two independent electromagnetic inductors located in the gap between the central part of the magnetic circuit and the object of testing has been developed. Inductors are two flat coils, each of them has form like a butterfly. The inductor conductors located in the working area have mutually perpendicular directions; they allow exciting and receiving the transversely polarized acoustic waves without rearranging the transducer. In order to reduce the overall dimensions and mass of the transducer, the mass and dimensional parameters of the magnetizing device were optimized for operating conditions when the magnetization of the object of testing and measurement are performed during the active measurement phase. During the passive measurement phase, which is three times longer than the active phase in time, the magnetizing device cools down. The cyclic mode with alternating active and passive phases made it possible to reduce the weight of the transducer by more than 3 times. In the working area of the transducer with a size of 15×15 mm, with a gap of 1 mm between the magnetic field concentrator and the object of testing, a field with a normal component of 2.4 T is created. The transducer has protection of the magnetization device from overheating, and the cyclic mode of operation allows for continuous performance of up to 30 measurements per minute at an ambient temperature of 20 °C.The developed magnetizing device can be used in solving a number of problems of structuroscopy, thickness measurement, flaw detection by electromagnetic-acoustic methods based on accurate measurement of the propagation time of elastic waves in the object of testing.