Exact Threshold Research Articles

A novel operational reliability and state prediction method based on degradation hidden Markov model with random threshold

AbstractBearings are widely used as a common mechanical component and significantly impacts the reliability and safety of various engineering equipment. In the field of large‐scale equipment such as wind turbines, statistical data for reliability and state prediction of bearings is usually limited, leading to the inapplicability of traditional statistical methods. Besides, individual differences commonly exist among bearings, and the appropriate failure threshold for a specific bearing is difficult to be determined due to the individual uncertainty, which may induce prediction errors. To address these issues, a novel operational reliability and state prediction method based on random threshold degradation hidden Markov model was proposed in the study. The traditional hidden Markov model was improved by considering the effect of performance degradation on state transition probability matrix. Moreover, random failure thresholds of performance degradation were employed to describe individual differences between bearings. The operational reliability and state of bearings was obtained by comprehensive analysis of prediction results under different failure thresholds. Verification of the proposed operational reliability and state prediction method were conducted using PHM2012 bearing operation data. The results underscored the effectiveness of the proposed method in achieving a comparatively high accuracy in operational reliability prediction without the prerequisite of an exact failure threshold, when contrasted with several established reliability and life prediction techniques.

The management of high flow arteriovenous fistula and possible solutions.

The development of a high flow rate arteriovenous fistula (AVF) can expose the patient to development of heart failure due to increased cardiac preload and pulmonary hypertension. AVF flow measurement (Qa) is considered a screening tool for AVF surveillance, aiming to evaluate the access dysfunction and prevent complications, like a non-maturation, suspected stenosis, high-flow AVF, and distal ischemia. In the upper arm AVF, a high Qa may develops, which can expose the patient to the risk of high-output heart failure and ischemia. Although, the exact threshold to define high-flow access is not universally accepted, AVF with a Qa of 1-1.5 L/min or cardio-pulmonary recirculation (Qa/CO) >20% are considered at risk. In our work we describe the treatment performed in three patients with high flow AVF treated with DRIL technique with interposition of a Prosthetic Patch, revascularization procedures such as distal inflow revision or RUDI and with innovative technique a "tench snout," removal the previous anastomosis and reconstruction of the integrity of the radial artery at the terminal in pre and post anastomosis. A PTFE prosthetic segment measuring 5 cm in length and 5 mm in diameter was interposed, terminally anastomosed with the efferent cephalic vein and terminally lateral with the radial artery, reducing the anastomosis to approximately 4 mm. All treated patients showed a clear improvement in the clinical picture in particularly heart failure. The calculation of the post-intervention flow rate approximately 1500 mL/min. The patient on hemodialysis with arteriovenous fistula must be constantly monitored with clinical examination, monitoring during the hemodialysis session and color Doppler ultrasound of the AVF with calculation of the flow rate. The surgical technique used for flow reduction is chosen on the surgical experience of each operator with the main objective of preserving the autologous AVF.

Comparative Analysis of Human and Artificial Intelligence Planning in Production Processes

Artificial intelligence (AI) has found applications in enterprises′ production planning processes. However, a critical question remains: could AI replace human planners? We conducted a comparative analysis to evaluate the main task of planners in an intermittent process: planning the duration of production orders. Specifically, we analysed the results of a human planner using master data and those of an AI algorithm compared to the actual realisation. The case study was conducted in a large production company using a sample of production products and machines. We were able to confirm two of the three research questions (RQ1 and RQ3), while the results of the third question (RQ2) did not meet our expectations. The AI algorithms demonstrated significant improvement with each iteration. Despite this progress, it is still difficult to determine the exact threshold at which AI outperforms human planners due to the unpredictability of unexpected events. Even though AI significantly improves prediction accuracy, the inherent variability and incomplete input data pose a major challenge. As progress is made, robust data collection and management strategies need to be integrated to bridge the gap between the potential of AI and its practical application, fostering the symbiosis between human expertise and AI capabilities in production planning.

Does the length of bypassed bowel during distal gastric bypass affect weight loss?

Weight recurrence (WR) affects > 20% of patients following Roux-en-Y gastric bypass (RYGB). Shortening of the common channel (CC) after RYGB (distal bypass) has been proposed for additional weight loss in patients with WR, but results vary, and concerns for vitamin deficiencies/malnutrition exist. Our aim was to determine whether the percentage of bowel bypassed after distal bypass is associated with the amount of postoperative weight loss. Patients undergoing distal bypass between 2018 and 2022 were reviewed. Small bowel limb lengths before and after distal bypass were measured, and the percentage of bypassed bowel was calculated (= bypassed biliopancreatic limb/total small bowel length). Patients were dichotomized into two groups based on the percentage bypassed bowel (≤ 50% vs. > 50%). Weight loss (measured as excess BMI loss; EBIL%), comorbidities resolution, complications, and nutritional deficiencies were reviewed. Thirty female patients underwent distal bypass during the study period. After distal bypass, the Roux was lengthened to 150cm (75-175cm) from 75cm (20-200cm), and the CC shortened to 150cm (100-310cm) from 510cm (250-1000cm). These changes resulted in an increase in the size of the bypassed biliopancreatic limb from 40cm (15-90cm) to 330cm (180-765cm) and a total alimentary limb (TALL; Roux + CC) shortening from 590cm (400-1075cm) to 300cm (250-400cm). The group with > 50% bowel bypassed had higher EBIL%. Overall EBIL% was 36.9 ± 14.7%, 53.3 ± 25.6%, and 62.1 ± 36.9% at 0.5, 1, and 2years, respectively. There were minimal vitamin deficiencies. Diabetes resolved in 100% (n = 3/3), HTN in 67% (n = 10/15), and GERD in 73% (n = 11/15). Complication rate was 23%. No reintervention for malnutrition or vitamin deficiencies was required. Distal bypass effectively leads to considerable weight loss and comorbidity improvement in patients with WR after RYGB, but the amount of weight loss depends on the percentage of bypassed bowel. An exact threshold of bypassed bowel that optimizes weight loss outcomes and simultaneously minimizes the nutritional complications needs to be determined. Meanwhile, close monitoring for vitamin deficiencies is recommended.

Threshold Interphase Delay for Bipolar Pulses to Prevent Cancellation Phenomenon during Electrochemotherapy.

Electroporation-based procedures employing nanosecond bipolar pulses are commonly linked to an undesirable phenomenon known as the cancelation effect. The cancellation effect arises when the second pulse partially or completely neutralizes the effects of the first pulse, simultaneously diminishing cells' plasma membrane permeabilization and the overall efficiency of the procedure. Introducing a temporal gap between the positive and negative phases of the bipolar pulses during electroporation procedures may help to overcome the cancellation phenomenon; however, the exact thresholds are not yet known. Therefore, in this work, we have tested the influence of different interphase delay values (from 0 ms to 95 ms) using symmetric bipolar nanoseconds (300 and 500 ns) on cell permeabilization using 10 Hz, 100 Hz, and 1 kHz protocols. As a model mouse hepatoma, the MH-22a cell line was employed. Additionally, we conducted in vitro electrochemotherapy with cisplatin, employing reduced interphase delay values (0 ms and 0.1 ms) at 10 Hz. Cell plasma membrane permeabilization and viability dependence on a variety of bipolar pulsed electric field protocols were characterized. It was shown that it is possible to minimize bipolar cancellation, enabling treatment efficiency comparable to monophasic pulses with identical parameters. At the same time, it was highlighted that bipolar cancellation has a significant influence on permeabilization, while the effects on the outcome of electrochemotherapy are minimal.

Isotope effects and Alfvén eigenmode stability in JET H, D, T, DT, and He plasmas

While much about Alfvén eigenmode (AE) stability has been explored in previous and current tokamaks, open questions remain for future burning plasma experiments, especially regarding exact stability threshold conditions and related isotope effects; the latter, of course, requiring good knowledge of the plasma ion composition. In the JET tokamak, eight in-vessel antennas actively excite stable AEs, from which their frequencies, toroidal mode numbers, and net damping rates are assessed. The effective ion mass can also be inferred using measurements of the plasma density and magnetic geometry. Thousands of AE stability measurements have been collected by the Alfvén Eigenmode Active Diagnostic in hundreds of JET plasmas during the recent Hydrogen, Deuterium, Tritium, DT, and Helium-4 campaigns. In this novel AE stability database, spanning all four main ion species, damping is observed to decrease with increasing Hydrogenic mass, but increase for Helium, a trend consistent with radiative damping as the dominant damping mechanism. These data are important for confident predictions of AE stability in both non-nuclear (H/He) and nuclear (D/T) operations in future devices. In particular, if radiative damping plays a significant role in overall stability, some AEs could be more easily destabilized in D/T plasmas than their H/He reference pulses, even before considering fast ion and alpha particle drive. Active MHD spectroscopy is also employed on select HD, HT, and DT plasmas to infer the effective ion mass, thereby closing the loop on isotope analysis and demonstrating a complementary method to typical diagnosis of the isotope ratio.

Factor analysis of traditional Chinese medicine symptoms for identification of syndrome patterns associated with idiopathic short stature in children.

Diagnosing idiopathic short stature (ISS) in Traditional Chinese Medicine (TCM) remains challenging partly because the symptoms and syndrome patterns vary among ISS patients and studies. We aimed to use factor analysis of TCM symptoms to identify syndrome patterns associated with ISS in children on the basis of TCM theory. A cross-sectional study was conducted at Taipei Tzu Chi Hospital, New Taipei City, Taiwan, from October 1, 2014, to February 28, 2016. The study included 957 individuals who were newly diagnosed with ISS through simple random sampling. The outcome measures comprised 34 TCM symptoms related to children's growth, and these symptoms were assessed using a five-level self-report questionnaire, which was completed by children and their parents. A factor analysis was conducted for the extraction of underlying factors. A total of 26 symptoms had factor loadings higher than the exact threshold value (0.4), and five factors were extracted. Factor 1, comprising seven symptoms, was interpreted as "yin deficiency and fire hyperactivity of kidney syndrome." Factor 2, which included eight symptoms, was interpreted as "phlegm dampness stagnation of spleen syndrome." Factor 4, which included five symptoms, was interpreted as "liver qi invading the spleen syndrome." Factor 5, which included four symptoms, was interpreted as "spleen-stomach weakness syndrome." Factor 3, which included four symptoms, was uninterpretable. Factors 1-5 accounted for 10%, 9%, 8%, 7%, and 6% of the total variance. Four major TCM syndrome patterns, namely, "yin deficiency and fire hyperactivity of kidney syndrome," "phlegm dampness stagnation of spleen syndrome," "Liver qi invading the spleen syndrome," and "spleen-stomach weakness syndrome" were identified and accounted for 40% of the total variance of the 34 TCM symptoms surveyed in children with ISS. Our findings may facilitate the diagnosis of ISS and the optimization of treatment strategies.

The Importance of Hypoxia-Related to Hemoglobin Concentration in Breast Cancer.

The importance of hemoglobin (Hgb) as a novel prognostic biomarker in predicting clinical features of cancers has been the subject of intense interest. Anemia is common in various types of cancer including breast cancer (BC) and is considered to be attributed to tumoral hypoxia. Cancer microenvironments are hypoxic compared with normal tissues, and this hypoxia is associated with Hgb concentration. Recent preclinical documents propose a direct or indirect correlation of intratumoral hypoxia, specifically along with acidity, with Hgb concentration and anemia. Analysis of the prognostic value of Hgb in BC patients has demonstrated increased hypoxia in the intratumoral environment. A great number of studies demonstrated that lower concentrations of Hgb before or during common cancer treatments, such as radiation and chemotherapy, is an essential risk factor for poor prognostic and survival, as well as low quality of life in BC patients. This data suggests a potential correlation between anemia and hypoxia in BC. While low Hgb levels are detrimental to BC invasion and survival, identification of a distinct and exact threshold for low Hgb concentration is challenging and inaccurate. The optimal thresholds for Hgb and partial pressure of oxygen (pO2) vary based on different factors including age, gender, therapeutic approaches, and tumor types. While necessitating further investigations, understanding the correlation of Hgb levels with tumoral hypoxia and oxygenation could improve exploring strategies to overcome radio-chemotherapy related anemia in BC patients. This review highlights the collective association of Hgb concentration and hypoxia condition in BC progression.

Anonymous Complaint Aggregation for Secure Messaging

Private messaging platforms provide strong protection against platform eavesdropping, but malicious users can use privacy as cover for spreading abuse and misinformation. In an attempt to identify the sources of misinformation on private platforms, researchers have proposed mechanisms to trace back the source of a user-reported message (CCS '19,'21). Unfortunately, the threat model considered by initial proposals allowed a single user to compromise the privacy of another user whose legitimate content the reporting user did not like. More recent work has attempted to mitigate this side effect by requiring a threshold number of users to report a message before its origins can be identified (NDSS '22). However, the state of the art scheme requires the introduction of new probabilistic data structures and only achieves a "fuzzy" threshold guarantee. Moreover, false positives, where the source of an unreported message is identified, are possible. This paper introduces a new threshold source tracking technique that allows a private messaging platform, with the cooperation of a third-party moderator, to operate a threshold reporting scheme with exact thresholds and no false positives. Unlike prior work, our techniques require no modification of the message delivery process for a standard source tracking scheme, affecting only the abuse reporting procedure, and do not require tuning of probabilistic data structures.

Cardiovascular mortality in patients with atrial fibrillation and physical activity intensity: delineating the threshold of vigorous activity

Abstract Background/Introduction There is a correlation between light-to-moderate physical activity and reduced atrial fibrillation (AF) incidence and cardiovascular risk. Vigorous activities reduced the benefits and increased the risk of AF. The exact threshold at which physical activity increases the risk of cardiovascular death (CVD) in patients with AF remains to be determined. Purpose To determine the threshold of vigorous activity in patients with AF. Methods In this study, data from 23856 individuals from the Taiwan Biobank (2017) were analyzed. Physical activity levels were quantified in metabolic equivalent task (MET) hours/week and categorized into four groups based on 20 MET-hour increments. The study employed Kaplan-Meier survival analysis and an adjusted generalized additive model (GAM) to assess the impact of physical activity on CVD risk (adjusting for age, sex, diabetes, hypertension, chronic obstructive pulmonary disease, and chronic kidney disease), with follow-up data from 2017 to 2022. Results Over a median 5.51-year follow-up, 238 AF cases (cumulative rate of AF: 0.998%) were identified (48.7% female, mean age 61.7 years). The linear model indicated a lower CVD risk in participants engaging in moderate physical activity (20-40 MET-hours/week; adjusted hazard ratio [HR]: 0.38, 95% CI: 0.16-0.95) compared to the reference group (0-20 MET-hours/week). Notably, the GAM model demonstrated a significant increase in CVD risk for activities exceeding 40 MET-hours/week after multivariable adjustment. Conclusions Physical activity levels and CVD risk in AF patients are correlated in a J-shaped manner. The CVD risk of AF decreased with mild to moderate physical activity. For AF patients, it establishes a critical threshold of 40 MET-hours/week beyond which there is an increased risk of CVD, thus clarifying safe physical activity limits.Figure 1:KM sruvival curveFigure 2:Smooth model of GAM

Optimal stopping decisions and the disposition effect

I conduct lab-in-the-field experiments using a stylized optimal stopping problem, through which I separately identify the exact threshold values for the disposition effect in the gain and loss domains. I further combine the experimental results with actual account-level trading records. Remarkably, I discover that solely the disposition effect indicator within the gain domain exhibits a positive correlation with the actual disposition effect observed in the stock market. This asymmetry in financial decision-making between the gain and loss domains suggests that individual investors may render suboptimal decisions primarily when confronted with gains.

X-ray signatures of galactic outflows into the circumgalactic medium

ABSTRACT We present a set of controlled hydrodynamical simulations to study the effects of strong galactic outflows on the density and temperature structures, and associated X-ray signatures, of extra-planar and circumgalactic gas. We consider three initial state models, isothermal, isentropic, and rotating cooling-flow, for the hot circumgalactic medium (CGM) into which the outflows are driven. The energy sources are either stellar winds and supernovae, or active galactic nuclei. We consider energy injection rates in the range $10^{40} \lt \dot{E}_{\rm inj} \lt 10^{44.5}$ erg s−1, and compute the time-dependent soft X-ray (0.5–2 keV) surface brightness. For $\dot{E}_{\rm inj} \gtrsim 10^{41} {\small --} 10^{42}$ erg s−1, with the exact threshold depending on the initial CGM state, the X-ray response is dominated by dense hot gas in the forward shock that eventually fades into the CGM as a sound wave. The shock surrounds an inner hot bubble leading to a radial flattening of the X-ray surface brightness. For lower energy injection rates, the X-ray surface brightness of the initial CGM state is almost unaffected. We present analytical approximations for the outflow shock propagation and the associated X-ray emissions.

Exact detection thresholds and minimax optimality of Chatterjee’s correlation coefficient

Exact detection thresholds and minimax optimality of Chatterjee’s correlation coefficient

Terahertz time-domain spectroscopy of nanoadditive macroscale superlubricity: Quantitative hydration investigation and deeper insight into the solid-liquid synergistic lubrication

As a promising approach, terahertz time-domain spectroscopy (THz-TDs) provides the powerful assistance for quantitatively characterizing the solid-liquid synergistic lubrication. The hydration ratio in nanoadditive solutions was calculated by terahertz dielectric spectrum, and the exact threshold for superlubricity was found as 40%. The high hydration ratio also promoted the formation of high-quality tribofilm. Besides, not all hydrogen bonds, but the solid-liquid hydrogen bond was the true answer to the nanoadditive superlubricity. Finally, a synergistic lubrication model was proposed and it gave a detailed description of the molecular states with different lubrication. This work exerts the sensitivity of THz-TDs on hydration and liquid lubrication, providing avenues for the quick assessment of superlubricity and optimal design of nanoadditive superlubricity in the future.

Multithreshold multipartite graphs with small parts

A graph is a k-threshold graph with thresholdsθ1,θ2,…,θk if we can assign a real number rv to each vertex v such that for any two distinct vertices u and v, uv is an edge if and only if the number of thresholds not exceeding ru+rv is odd. The threshold number of a graph is the smallest k for which it is a k-threshold graph. Multithreshold graphs were introduced by Jamison and Sprague as a generalization of classical threshold graphs. They asked for the exact threshold numbers of complete multipartite graphs. Recently, Chen and Hao solved the problem for complete multipartite graphs where each part is not too small, and they asked for the case when each part has size 3. We determine the exact threshold numbers of K3,3,…,3, K4,4,…,4 and their complements nK3, nK4. This improves a result of Puleo.

The Role of Bone Mineral Density in a Successful Lumbar Interbody Fusion: A Narrative Review.

The incidence of osteoporosis is a prime concern, especially in parts of the world where the population is aging, such as Europe or the US. Many new therapy strategies have been described to enhance bone healing. Lumbar interbody fusion (LIF) is a surgical procedure that aims to stabilize the lumbar spine by fusing two or more vertebrae using an interbody cage. LIF is a standard treatment for various spinal conditions, such as degenerative disc disease, spinal stenosis, and spondylolisthesis. However, successful fusion is challenging for patients with osteoporosis due to their reduced bone mineral density (BMD) and increased risk of cage subsidence, which can lead to implant failure and poor clinical outcomes. A comprehensive literature search yielded 220 articles, with 16 ultimately included. Keywords included BMD, cage subsidence, osteoporosis, teriparatide, and lumbar interbody fusion. This review examines the relationship between BMD and LIF success, emphasizing the importance of adequate bone quality for successful fusion. Preoperative assessment methods for BMD and the impact of low BMD on fusion rates and patient outcomes are discussed. Additionally, techniques to improve fusion success in patients with weakened bone density, such as biological enhancement and BMD-matched interbody cages, are explored. However, consensus on the exact BMD threshold for a successful outcome remains elusive. While an apparent correlation between BMDand fusion rate in LIFprocedures is acknowledged, conclusive evidence regarding the precise BMD threshold indicative of an increased risk of unfavorable outcomes remains elusive.Surgeons are advised to exercise caution in surgical planning and follow-up for patients with lower BMD.Furthermore, future research initiatives, particularly longitudinal studies, are encouraged to prioritize the examination of BMD as a fundamental risk factor, addressing gaps in the literature.

Exponential Capacity of Dense Associative Memories.

Recent generalizations of the Hopfield model of associative memories are able to store a number P of random patterns that grows exponentially with the number N of neurons, P=exp(αN). Besides the huge storage capacity, another interesting feature of these networks is their connection to the attention mechanism which is part of the Transformer architecture widely applied in deep learning. In this work, we study a generic family of pattern ensembles using a statistical mechanics analysis which gives exact asymptotic thresholds for the retrieval of a typical pattern, α_{1}, and lower bounds for the maximum of the load α for which all patterns can be retrieved, α_{c}, as well as sizes of attraction basins. We discuss in detail the cases of Gaussian and spherical patterns, and show that they display rich and qualitatively different phase diagrams.

Asymmetric threshold effects of digitization on inflation in emerging markets

This paper analyzes the dynamic asymmetric effects of digitization on domestic inflation for a sample of 54 advanced economies (AEs) and emerging markets (EMs) over the period 2004–2018. Using Katz and Calorda’s Digital Ecosystem Development Index and employing the system Generalized Method of Moments (GMM) estimation methodology, the results of the paper reveal that the improvement in digitization has a statistically significant nonlinear deflationary effect with an exact threshold level of 43.22 points, that is, that the marginal effect of the digital penetration is larger when its level is lower than the threshold level. For EMs, with a level of digitization below the average of our full sample, policymakers must continue to invest in and expand on their digital ecosystem until the threshold level is achieved. Our results show that investment in human capital and improvement in governance can reinforce these deflationary effects. Hence, to obtain the maximum positive impact of increasing digitization on domestic inflation, EM governments should focus on maximizing school enrollment, controlling corruption, establishing rule of law, protecting the right to freedom of opinion and expression, and implementing accountability measures.

Distinguishing probable atypical anorexia nervosa from weight loss alone in a national sample of U.S. Military Veterans: Disentangling the roles of weight suppression and cognitive concerns.

Veterans are at high risk for eating disorders (EDs), and specifically for atypical anorexia nervosa (atypical AN). The current study aimed to better understand this under-studied disorder and how it differs from weight loss without ED cognitive features. Secondary analyses were conducted with data from a national study of Veterans (N = 882, 49.4% women). Participants were categorized into four mutually exclusive groups using the Eating Disorder Diagnostic Scale 5: probable atypical AN, a cognitive concerns group (Cog Only), a weight suppressed group (WS Only), and a no ED control group. Adjusted regression models were used to compare groups on measures of eating pathology and mental health. Three weight suppression thresholds (5%, 10%, and 15%) for probable atypical AN were also tested. The sample was comprised of 12% probable atypical AN, 23.6% Cog Only, 16.3% WS Only, and 48.1% Control. The probable atypical AN group was most like the Cog Only group except for higher levels of dietary restraint. Atypical AN fared worse and was least like the Control group followed by the WS Only group. All weight suppression thresholds significantly predicted dietary restraint, with 5% being the best predictor. Results found that probable atypical AN is a distinct clinical entity and that the exact weight suppression threshold associated with atypical AN is less important than having any weight suppression. Findings highlight the clinical significance of atypical AN and the importance of gaining a better understanding of how to address this clinical entity. Atypical anorexia nervosa is a relatively underexamined but highly prevalent eating disorder in the Veteran population. Results show that ED cognitive features are more closely linked to clinically significant eating pathology and poor mental health than weight suppression alone suggesting that negative thinking about weight gain and appearance, regardless of the presence or severity of weight loss, may signal the need for specialized intervention.

THE USE OF AN ULTRASONIC TOOL TO CUT HUMAN BONE: CUTTING SPEED AND FORCES OF ORTHOPAEDIC SURGEONS

AbstractBackgroundUltrasonic cutting of bone boasts many advantages over alternatively powered surgical instruments, including but not limited to: elimination of swarf, reduced reaction forces, increased precision in cutting and reduced adjacent soft tissue damage, reduced post-operative complications such as bleeding and bone fracture, reduced healing time, reduced intra-operative noise and ease of handling. Despite ultrasonic cutting devices being well established in oral and maxillofacial surgery, applications in orthopaedic surgery are more niche and are not as well understood. The aim of this study was to investigate the cutting speed (mm/s) and cutting forces (N) of orthopaedic surgeons using a custom-designed state of the art ultrasonic cutting tool to cut fresh human bone samples.MethodsA setup based on the Robot Operating System (ROS) and AprilTag was designed to track and to record the real time position of the ultrasonic cutting tool in space. Synchronised load cell axial force readings of three separate orthopaedic surgeons during ultrasonic cutting were recorded. Each surgeon was asked to find a comfortable position that reflects as close as possible their clinical handling of a cutting instrument used in surgery, and to perform two cuts in each of three samples of human cortical bone. Bone samples were obtained following ethical approval from an institutional review board (ethics approval number: SR1342) and prior informed consent was obtained from all patients. Bone samples were extracted from the femoral neck region of three hip osteoarthritis patients. During cutting, surgeons were allowed a total cutting time of one minute and cutting was conducted using an ultrasonic tool with frequency of a 35kHz (35.7 µm peak to peak displacement amplitude) under constant irrigation using a MINIPULS® 3 Peristaltic pump (38 revolutions per minute) using Phosphate-Buffered Saline (PBS) at 25°C. From the recorded data, the average instantaneous cutting velocity was calculated and the maximum cutting force was identified.ResultsAll surgeons assumed a back-and-forth cutting motion, variation in the applied cutting force was observed. The average vertical cutting speed, axial cutting force and cutting depth across all surgeons and all samples was 1.64 mm/s, 1.91 N and 0.73 mm, respectively. While increasing the axial cutting force resulted in a deeper cut, overloading of the ultrasound transducer occurred when the tool advanced too quickly into the bone tissue during cutting. The exact force threshold, or the optimal speed at which the surgeon can maintain a constant force during cutting, requires further investigation.ConclusionsIn this study, all surgeons cut using a back-and-forth cutting motion, with variation in the applied cutting force which may ultimately inform which clinical applications in orthopaedic engineering are most suitable for this technology. Applying too much force caused overloading of the ultrasound transducer, which is a limitation with the current cutting tool. The results from this study may facilitate the eventual uptake of ultrasonic cutting tools for application in orthopaedic surgery.Declaration of Interest(b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.