Flow Rate Measurement of Gravity Infusion Set and Functional Evaluation of Drop Counter: A Pilot Study

Developing a novel drop counter by introducing the Internet of Things concept has been vigorously conducted in recent years. Understanding the newly introduced drop counter’s flow rate control accuracy and flow rate count feature is essential for improving safety in infusion management. This study aimed to verify if the new drop counters could secure accurate flow rate and drip count by conducting actual flow rate measurements using gravimetry and functional evaluation. A drop counter was attached to each drip chamber of the infusion set, and an IV drip was conducted at the 100 ml/h flow rate. The weight of discharged physiological saline was measured to plot trumpet curves. Next, three different types of drop counters were evaluated to determine if they maintained drip count accuracy according to the changes in their position angles. The flow rate errors in all conditions indicated trumpet-like curves, exhibiting an overall error range within ±10% in all observation windows. Although every drop counter successfully detected and measured dripping, it was challenging in some counters to detect dripping when the drip chamber was tilted. In comparing adult and pediatric IV sets, the adult IV set was found to be less likely to detect dripping in the angled position. No significant differences in results were confirmed between high and low flow rates, suggesting that the drop count function would not be affected by the flow rate in the ranges of typical infusion practices. Doppler sensors have a wide range of measurements and high sensitivity;the dripping was detected successfully even when the drip chamber was tilted, probably due to the advantages of these sensors. In contrast, miscounts occurred in those equipped with infrared sensors, which could not detect light intensity changes in tilted positions. Understanding the tendencies in flow rate errors in infusion can be valuable information for infusion management.

Stresses in the Scapular Fossa Do Not Exceed the Yield Stress When Elevated up to 135 Degrees of Abduction after Reverse Shoulder Arthroplasty

Reverse shoulder arthroplasty (RSA) is an effective treatment for rotator cuff tears. Despite its advantages, complications occur at a high rate. Complications requiring revision include a high rate of base plate failure, 38% of which are due to instability. The primary stability the base plate ensures is a crucial factor and, thus, is the subject of much debate in clinical studies and biomechanical research. This study is aimed to provide data that will contribute to the base plate’s pri-mary stability and glenoid longevity by clarifying the stresses at the scapular fossa and base plate interface associated with elevation after RSA. A 3D finite element model was created from the DICOM data for the scapulohumeral joint and SMR shoulder system. For loading conditions, 30 N was applied for each posi-tion with abduction angles of 0, 45, 90, and 135 degrees. A three-dimensional fi-nite element analysis was performed using the static implicit method with LS-DYNA. The von Mises stresses in the scapular fossa were found not to exceed the yield stress on the bone even after elevation to an abduction angle of 135 de-grees after RSA. It is rough to uniformly compare the yield stress and the von Mises stress, but it was inferred that the possibility of fracture is low unless a large external force is applied. A maximum von Mises stress showed 0 degrees of abduction, suggesting that the lowered position is in a more severe condition than the elevated position. If better improvement is desired, it may be necessary to devise ways to reduce the stress on the upper screw. .

Predicting the number of visceral leishmaniasis cases in Kashgar, Xinjiang, China using the ARIMA-EGARCH model

Objective:To forecast the visceral leishmaniasis cases using autoregress integrated moving average(ARIMA)and hybrid ARIMAEGARCH model,which offers a scientific basis to control visceral leishmaniasis spread in Kashgar Prefecture of Xinjiang,China.Methods:The data used in this paper are monthly visceral leishmaniasis cases in the Kashgar Prefecture of Xinjiang from 2004 to 2016.The sample data between 2004 and 2015 were used for the estimation to choose the best model and the sample data in 2016 were used for the forecast.Time series of visceral leishmaniasis started on 1 January 2004 and ended on 31 December 2016,consisting of 1790 observations reported in Kashgar Prefecture.Results:For Xinjiang,the total number of reported cases were 2187,the male-to-female ratio of cases was 1:1.42.Patients aged between 0 and 10 years accounted for 82.72%of all reported cases and the largest percentage of visceral leishmaniasis cases was detected among scattered children who accounted for 68.82%.The monthly incidences fitted by ARIMA(2,1,2)(1,1,1)12 model were consistent with the real data collected from 2004 to 2015.However,the predicted cases failed to comply with the observed case number;we then attempted to establish a hybrid ARIMA-EGARCH model to fit visceral leishmaniasis.Finally,the ARIMA(2,1,2)(1,1,1)12-EGARCH(1,1)model showed a good estimation when dealing with volatility clustering in the data series.Conclusions:The combined model has been determined as the best prediction model with the root-mean-square error(RMSE)of 7.23%in the validation phase,which means that this model has high validity and rationality and can be used for short-term prediction of visceral leishmaniasis and could be applied to the prevention and control of the disease.

Investigation of Hammering Sound Frequency to Prevent Intraoperative Fracture during Total Hip Arthroplasty

Background: The 1st peak frequency of the hammering sound in total hip arthroplasty may serve as an evaluation index to prevent intraoperative fracture. Fixation of the stem and femur cannot be acquired unless the 1st peak frequency of hammering the stem into the femur stabilizes, and fixation can be judged as acquired when the 1st peak frequency becomes constant. To investigate whether the environmental sound in the operating room can be differentiated from the hammering sound of total hip arthroplasty, the 1st peak frequency of the hammering sound when impacting the stem into the femur with a hammer was identified. Method: The hammering sound of impacting the stem into a biomechanical test material through an impactor was analyzed using a fast Fourier transform analyzer. Environmental sound in the operating room was simulated and the 1st peak frequency of the sound on collision between the operator’s voice and the surgical instrument was measured. The 1st peak frequency of hammering sound was compared between patients indicated for total hip arthroplasty and healthy individuals to investigate whether there is a difference due to bone quality. Results: The natural frequency of the impactor was 3.41 ± 0.05 kHz, and the 1st peak frequency of the femur, stem, and impactor was 2.43 ± 1.45 kHz. The 1st peak frequency of hammering sound on simulated femur in patients indicated for total hip arthroplasty was 2.98 ± 0.73 kHz and that in healthy individuals was 2.15 ± 0.32 kHz. This suggested that the hammering sound in total hip arthroplasty-indicated patients overlaps with the frequency of the collision sound of surgical instruments. Conclusion: To develop a system to prevent intraoperative fracture, countermeasures, such as noise canceling, are necessary to prevent false detection of hammering sounds.

Selection of Hammering Sound Collection Devices for the Development of Total Hip Arthroplasty Support Systems

In total hip arthroplasty, intraoperative femoral fractures can be avoided by analyzing the hammering sounds from the stem inserted into the femur. This procedure is based on a hammering test that makes use of the fact that sound depends on the stability of the object. This technique is generally used in engineering. A system designed to avoid excessive stem hammering by predicting the intraoperative fracture risk based on this technique and software for real-time spectra analysis has been developed with repetitive improvements. The remaining technical challenge lies in selecting an appropriate sound collection device and building a compact and easy unit for use. This study reviewed the types of directional microphones suitable for the sound collection system to develop a practical THA support system. Four types of microphones based on selected methods were used to collect and compare the peak frequencies of the hammering sounds and make comparisons between them, and the built system was used to conduct clinical trials. For miniaturization and operational ease of the unit, plug-in unidirectional microphones are appropriate. However, no laboratory-level data has been collected, and thus, further data accumulation is necessary.

Analysis and simulation of a stochastic COVID-19 model with large-scale nucleic acid detection and isolation measures: A case study of the outbreak in Urumqi, China in August 2022

In this paper,a stochastic COVID-19 model with large-scale nucleic acid detection and isolation measures is proposed.Firstly,the existence and uniqueness of the global positive solution is obtained.Secondly,threshold criteria for the stochastic extinction and persistence in the mean with probability one are established.Moreover,a sufficient condition for the existence of unique ergodic stationary distribution for any positive solution is also established.Finally,numerical simulations are carried out in combination with real COVID-19 data from Urumqi,China and the theoretical results are verified.

Structural and electronic properties of chiral single-wall copper nanotubes

The structural,energetic and electronic properties of chiral(n,m)(3≤n≤6,n/2≤m≤n)single-wall copper nanotubes(CuNTs)have been investigated by using projector-augmented wave method based on density-functional theory.The(4,3)CuNT is energetically stable and should be observed experimentally in both free-standing and tip-suspended conditions,whereas the(5,5)and(6,4)CuNTs should be observed in free-standing and tip-suspended conditions,respectively.The number of conductance channels in the CuNTs does not always correspond to the number of atomic strands comprising the nanotube.Charge density contours show that there is an enhanced interatomic interaction in CuNTs compared with Cu bulk.Current transporting states display different periods and chirality,the combined effects of which lead to weaker chiral currents on CuNTs.

Vibration Signal Analysis for Detecting Early-Stage Lumbar Spondylolysis Using Synthetic Bone

Bone fractures can be detected by analyzing vibration signals following bone stimulation. This method can also be applied to detect stress fractures, such as spondylolysis. The aim of this study was to investigate whether vibration signal analysis can be used to detect lumbar spondylolysis in synthetic bone. Four synthetic spondylolysis models of the fifth lumbar vertebra (Sawbones, product No. SAW1352-10: Malm&#246;, Sweden) were prepared, with the following conditions: intact, unilateral defect, and bilateral defect. Unilateral defects were created by making an incision of either half the diameter (50% incision) or the entire diameter (100% incision) in length through the pars interarticularis or pedicle. Bilateral defects were created by making an additional incision of half the diameter in length on the opposite side of the defected pars interarticularis or pedicle (50% + 100% incision). Hammering was performed five times on each spinous process of the fixed synthetic bones and vibration signals were measured using an accelerometer attached to the contralateral side of the hammer. Signals were analyzed using fast Fourier transform. The parameters analyzed included the mean power frequency, first power minimum frequency (the minimum value between the first and second peaks), spectral areas of low and high frequency bands, and the relative ratio between the spectral areas of low and high frequency bands. The relative ratio was significantly lower in the 50%, 100%, and 50% + 100% incision conditions compared to the intact condition (p < 0.01), suggesting the potential utility of vibration signal analysis in diagnosing lumbar spondylolysis.

Modelling COVID-19 outbreak on the Diamond Princess ship using the public surveillance data

The novel coronavirus disease 2019(COVID-19)outbreak on the Diamond Princess(DP)ship has caused over 634 cases as of February 20,2020.We model the transmission process on DP ship as a stochastic branching process,and estimate the reproduction number at the innitial phase of 2.9(95%CrI:1.7e7.7).The epidemic doubling time is 3.4 days,and thus timely actions on COVID-19 control were crucial.We estimate the COVID-19 transmissibility reduced 34%after the quarantine program on the DP ship which was implemented on February 5.According to the model simulation,relocating the population at risk may sustainably decrease the epidemic size,postpone the timing of epidemic peak,and thus relieve the tensive demands in the healthcare.The lesson learnt on the ship should be considered in other similar settings.