Applied Sciences

ObjectivesThe diagnosis of vocal fold cancer currently relies on invasive surgical biopsies, which can compromise laryngeal function. Distinguishing between different types of laryngeal lesions without invasive tissue sampling is therefore crucial. Autofluorescence spectroscopy (AFS) has proved to be efficient as a non-invasive detection technique but has yet to be fully exploited in the context of a multi-class tissue analysis. This study evaluates whether AFS can be used to discriminate between different types of laryngeal lesions in view of assisting in vocal fold surgery and preoperative investigations. Materials and methodsEx vivo spectral autofluorescence scans were recorded for each sample using a 405-nm laser excitation. A total of 1308 spectra were recorded from 29 vocal fold samples obtained from 23 patients. Multiclass analysis was conducted on the spectral data, classifying lesions either as normal, benign, dysplastic, or carcinoma. The results were compared to histopathological diagnosis. ResultsThrough an appropriate selection of spectral components and a cascading classification approach based on artificial neural networks (ANN), a classification rate of 97% was achieved for each lesion class, compared to 52% using autofluorescence intensity. ConclusionThe study demonstrates the effectiveness of AFS combined with multivariate analysis for accurate classification of vocal fold lesions. Comprehensive spectral data analysis significantly improves classification accuracy, even in challenging situations such as distinguishing between malignant and premalignant or benign lesions. This method could provide a way to perform in situ mapping of tissue states for minimally-invasive biopsy and surgical resection margins.

Wear of the inlay in total knee arthroplasty (TKA) contributes to implant failure and the need for revision surgery. In vivo wear assessment is challenging owing to the radiolucency of the inlay in standard radiographs. This study aimed to investigate the basic feasibility of integrating radiopaque X-ray markers on standard inlays to enhance their radiographic visibility and enable wear evaluation. Preliminary experiments identified optimal process parameters for micro-milling cavities on ultra-high molecular weight polyethylene (UHMWPE). A total of 450 parameter combinations were evaluated, with burr formation serving as the quality criterion. A process chain, comprising pre-contouring, micro-milling, filling cavities with radiopaque composite, and final contouring, was developed for inlay production. Eleven inlays with varying marker alignments, orientations, and geometries were manufactured, featuring grooves ([≤]0.8 mm wide) and holes (diameter = 1.6 mm), both 1 mm deep. Three HDPE + BaSO composites (10, 20, and 30 wt.% BaSO) were formulated and assessed for radiopacity per ASTM F640-20. Final marker cavities were filled with HDPE + 20 wt.% BaSO via pellet extrusion. The inlays were positioned in a phantom knee setup and radiographed in the anteroposterior view. Projected markers were evaluated based on edge visibility, measurability, homogeneity, and obscuration by the implant. None of the parameter combinations resulted in burr-free cavities, indicating an unstable five-axis process. X-ray images revealed that grooves aligned in the X-ray direction and drilled holes exhibited the best visibility for wear markers. Pin-on-plate tribological experiments revealed that BaSO addition to pure HDPE reduced its CoF from 0.25 to 0.1, reaching a value comparable to UHMWPE (0.15), while also enhancing wear resistance. This study demonstrated the feasibility of integrating wear markers on standard TKA inlays by micro-milling cavities at different positions and orientations on the inlay surface and filling them with a radiopaque composite. Further research is required to optimise process parameters and investigate marker wear.

ObjectivesA previously published biomechanical study of axial cyclic testing on a lockingtype plating system presented several failure types of the screw-plate interfaces (SPI). It was assumed that increasing micromotions of SPIs result consequently in initial failure of SPIs during cyclic loading. In conclusion, measurements of SPIs via digital image correlation (DIC) were suggested to detect potential micromotions. MethodsDIC measurements were performed using the ARAMIS Adjustable 3D measurement system to track the surface of the screw-head and bone plate during cyclic testing to determine potential micromotions. The micromotion is thereby described as the change in distance of the screw-head center to a reference point on the bone plate, providing information about the quality of interlocking of the related SPI during cyclic loading. Micromotion analysis was performed on the fracture-adjacent SPIs of the implant system, that were considered as the most relevant interfaces. ResultsMicromotion could be detected for both facture-adjacent SPIs in all test samples with increasing magnitude during cyclic testing, resulting in micromotions up to 587 {micro}m for the proximal and 321 {micro}m for the distal fracture-adjacent SPI after 50k load cycles. The strongest increase in micromotion could thereby be detected within early stages of cyclic loading. ConclusionsThe approach to determine micromotions of SPIs during axial cyclic loading was successful, indicating a reduction of the SPI s quality of interlocking as micromotions increase during cyclic loading of the tested locking-type implant system.

Soft tissue deformation(STD) causes the most prominent source of error in skin marker (SM) based motion analysis, commonly referred to as Soft Tissue Artifact (STA). To compensate for its effect and to accurately assess in vivo joint kinematics, quantification of STD in three-dimension (3D) is essential. In the literature, different invasive and radiological approaches have been employed to study how STA propagates in joint kinematics. However, there is limited reference data extensively reporting distribution of the artifact itself in 3D. The current study was thus aimed at quantifying STD in 10 subjects along three anatomical directions. Biplanar X-ray system was used to determine true bone and SM positions while the subjects underwent quasi-static single leg flexion. STD exhibited inter-subject similarity. A non-uniform distribution was observed at the pelvis, thigh and shank displaying maximum at the thigh (up to 18.5 mm) and minimum at the shank (up to 8 mm). STD at the pelvis and thigh displayed inter-marker similarity. STD at the pelvis was found direction independent, showing similar distribution in all the 3 directions. However, the thigh and shank exhibited higher STD in the proximal-distal direction of the bone embedded anatomical reference frame. These findings may provide more insights while interpreting motion analysis data as well to effectively strategize STA compensation methods.

Acoustic simulations of cochlear implants (CIs) allow for studies of perceptual performance with minimized effects of large CI individual variability. Different from conventional simulations using continuous sinusoidal or noise carriers, the present study employs pulsatile Gaussian-enveloped tones (GETs) to simulate several key features in modern CIs. Subject to the time-frequency uncertainty principle, the GET has a well-defined tradeoff between its duration and bandwidth. Two types of GET vocoders were implemented and evaluated in normal-hearing listeners. In the first implementation, constant 100-Hz GETs were used to minimize within-channel temporal overlap while different GET durations were used to simulate electric channel interaction. This GET vocoder could produce vowel and consonant recognition similar to actual CI performance. In the second implementation, 900-Hz/channel pulse trains were directly mapped to 900-Hz GET trains to simulate the maxima selection and amplitude compression of a widely-used n-of-m processing strategy, or the Advanced Combination Encoder. The simulated and actual implant performance of speech-in-noise recognition was similar in terms of the overall trend, absolute mean scores, and standard deviations. The present results suggest that the pulsatile GET vocoders can be used as alternative vocoders to simultaneously simulate several key CI processing features and result in similar speech perception performance to that with modern CIs.

Introduction and ObjectiveNear-infrared (NIR) fluorescence is used to visualize anatomical structures and physiological activities in real time. The objective is to synthesize the advantages and disadvantages of the PTeye system in the identification of parathyroid glands during thyroid and parathyroid surgery. MethodA literature review of the scope of primary research articles in databases such as PubMed, WoS and Cochrane was carried out, using the search strategy "(autofluorescence AND (parathyroid glands)) AND PTeye" until January 27, 2025. We included studies with any methodology that evaluated the identification of parathyroid glands with autofluorescence in thyroid or parathyroid surgery with PTeye technology. Review articles, editorials, and individual clinical cases were excluded. ResultsWe included 8 studies that met the inclusion criteria. The results showed that PTeye has high accuracy in identifying parathyroid glands, with identification rates above 90%. The use of PTeye reduced the need for additional tests such as freeze biopsies and increased the surgeons confidence in identifying parathyroid tissue. However, some false positives were identified, including thyroid nodules and lymph nodes. The device proved to be easy to use and provided real-time feedback. ConclusionsPTeye is a useful tool to improve the identification of parathyroid glands during surgery, increasing surgeon confidence and reducing the rate of postoperative hypocalcemia. Although it has some disadvantages, such as the possibility of false positives and the need for a learning curve, its benefits outweigh these limitations. More studies are needed to confirm these findings and assess their long-term impact.

BackgroundNowadays, the internal fixation has been an effective way for calcaneal fractures treatment. However, high risk of infection was found after the internal fixation, and the mechnism remains unclear. ObjectiveIn this work, we systematically preformed a comparative proteomic analysis between necrotic tissues and normal soft tissues aiming to find the molecular changes of the tissue during the fixation. MethodThe necrotic tissues (NTs) samples (n = 3) and the normal soft tissues control (NC) samples (n = 3) which was 2 -3 cm away from the NT were collected after the surgery. ALC-MS/MS analysis. A label free quantitation stragy was used to compare the proteome alterations followed by detailed bioinformatic analysis. ResultsA total of 902 and 1286 protein groups were quantified in the NT group and the NC group separately, with 233 proteins upregulated and 484 proteins downregulated in the NT group. Those differently expressed proteins were highly correlated with the metabolic pathways, especially those downregulated proteins in the necrotic tissue indicating an inacitive cell states in the nearby of the plate internal fixation. In addition, the detailed functiona analysis showed that the the upregutated proteins in necrotic tissue were highly enriched in the disease-related functions. ConclusionThis alerted us to clean the wound in time and found a safer strategy for internal fixation. Altogether, the emerging understanding of the proteomic properties in the necrotic tissue will guide the development of new strategies for internal fixation of calcaneal fractures

Anterior cruciate ligament (ACL) injury and ACL reconstruction (ACLR) surgery are common. Many ACL-injured subjects develop osteoarthritis within a decade of injury, a major cause of disability without cure. Laboratory-based biomechanical assessment can evaluate ACL injury risk and rehabilitation progress after ACLR; however, lab-based measurements are expensive and inaccessible to a majority of people. Portable sensors such as wearables and cameras can be deployed during sporting activities, in clinics, and in patient homes for biomechanical assessment. Although many portable sensing approaches have demonstrated promising results during various assessments related to ACL injury, they have not yet been widely adopted as tools for ACL injury prevention training, evaluation of ACL reconstructions, and return-to-sport decision making. The purpose of this review is to summarize research on out-of-lab portable sensing applied to ACL and ACLR and offer our perspectives on new opportunities for future research and development. We identified 49 original research articles on out-of-lab ACL-related assessment; the most common sensing modalities were inertial measurement units (IMUs), depth cameras, and RGB cameras. The studies combined portable sensors with direct feature extraction, physics-based modeling, or machine learning to estimate a range of biomechanical parameters (e.g., knee kinematics and kinetics) during jump-landing tasks, cutting, squats, and gait. Many of the reviewed studies depict proof-of-concept methods for potential future clinical applications including ACL injury risk screening, injury prevention training, and rehabilitation assessment. By synthesizing these results, we describe important opportunities that exist for using sophisticated modeling techniques to enable more accurate assessment along with standardization of data collection and creation of large benchmark datasets. If successful, these advances will enable widespread use of portable-sensing approaches to identify ACL injury risk factors, mitigate high-risk movements prior to injury, and optimize rehabilitation paradigms.

Cobbs traditional method for measuring the angle of scoliosis is complicated and error-prone in application. Angles measured with this method are inaccurate and it therefore stands to reason to search for improved procedures. We propose Cobbs angle to be determined by two novel methods: the distance method and the two-angle method. Using mathematical error analysis and experimental test measurings we demonstrate that the two proposed methods offer significant advantages over the current standard. They simplify the measurement process and increase outcome accuracy. For Cobbs angles larger than 30 degrees, the two-angle method reduces the error-variation by approx. 25%. For Cobbs angles below 30 degrees the distance method reduces the error-variation by approx. 50%.

The ability to discern variations in voice quality from speech is important for effective talker identification and robust speech processing; yet, little is known about how faithfully acoustic information relevant to variations in talkers voice quality is transmitted through a cochlear implant (CI) device. The present study analyzed unprocessed and CI-simulated versions of sustained /a/ vowel sounds from two groups of individuals with normal and disordered voice qualities in order to explore the effects of CI speech processing on acoustic information relevant for the distinction of voice quality. The CI-simulated voices were created by processing the vowel sounds along with 4-, 8-, 12-, 16-, 22-, and 32-channel noise-vocoders. The variations in voice quality for each voice sound was characterized by calculating mel-frequency cepstral coefficients (MFCCs). The effects of simulated CI speech processing on the acoustic distinctiveness between normal and disordered voices were then measured by calculating the Mahalanobis distance (MD) metric, as well as accuracy of support vector machines (SVMs) applied to MFCC features. The results showed that CI speech processing, as simulated by noise vocoding, is highly detrimental to the acoustic information involved in conveying voice quality distinctions. This supports the view that listeners with CIs will likely experience difficulties in perceiving voice quality variations due to the reduced spectral resolution, shedding light on challenges listeners with CIs may face for effective recognition and processing of talkers voices.

BackgroundThe acetabular pathomorphology in patients with Crowe type II and III developmental dysplasia of the hip(DDH)often present complicated changes, which bring challenges to the anatomical reconstruction of acetabulum in total hip arthroplasty (THA). The objective of this study was to develope a novel 3D printed integral customized acetabular prosthesis, which provides a promising way to reconstruct the acetabulum with higher accuracy and efficiency by digital softwares, compared with previous 3D printing model method. Methods15 patients (18 hips) with end-stage hip osteoarthritis due to Crowe type II/III DDH who underwent primary cementless THA from January 2015 to November 2021 were included. The 15 patients consisted of 3 men (3 hips) and 12 women (15 hips) with an average age of 53.89 {+/-} 8.48 years (range from 32 to 69 years). The novel 3D printed integral customized acetabular prosthesis was designed by the model method and software method respectively. The indicators of the cup size, the volume and superficial area of bone defect, the inclination and anteversion of acetabular cup, the horizontal and vertical distance of hip center and working time were compared between two methods. ResultsThere were statistically significant difference between the software group and model group on the volume and superficial area of bone defect as well as working time (t = 2.397, 2.707,138.509, P < 0.05). The mean anteversion and inclination of acetabular cup in the software group and model group were(15.17{+/-}0.52){degrees},(40.24{+/-}0.58){degrees}and (33.79 {+/-}13.43){degrees}, (30.50 {+/-}11.03){degrees}respectively, the difference was statistically significant (t = 5.859, 3.767, P < 0.05).There were no statistically significant difference between the software group and model group on cup size, the horizontal and vertical distance of hip center(t =1.458,0.114, 1.712, P > 0.05) ConclusionsThe application of digital softwares could design and develope the novel 3D printed integral customized anatomical acetabular prosthesis in THA for {square}Crowe type II and III DDH with high accuracy and efficiency.

PurposeThis study aims to use proteomic profiling of sonicate fluid samples to compare host response during Staphylococcus aureus-associated periprosthetic joint infection (PJI) and non-infected arthroplasty failure (NIAF) and investigate novel biomarkers to increase diagnostic accuracy. Experimental DesignIn this pilot study, eight sonicate fluid samples (four from NIAF and four from Staphylococcus aureus PJI) were studied. Samples were reduced, alkylated and trypsinized overnight, followed by analysis using liquid chromatography-tandem mass spectrometry (LC-MS/MS) on a high-resolution Orbitrap Eclipse mass spectrometer. MaxQuant software suite was used for protein identification, filtering, and label-free quantitation. ResultsPrincipal component analysis of the identified proteins clearly separated S. aureus PJI and NIAF samples. Overall, 810 proteins were quantified in any three samples from each group and 35 statistically significant differentially abundant proteins (DAPs) were found (2-sample t-test p-values [&le;]0.05 and log2fold-change values [&ge;]2 or [&le;]-2). Gene ontology pathway analysis found that microbial defense responses, specifically those related to neutrophil activation, were increased in S. aureus PJI compared to NIAF samples. Conclusion and Clinical RelevanceProteomic profiling of sonicate fluid using LC-MS/MS, alone or in combination with complementary protein analyses, differentiated S. aureus PJI and NIAF in this pilot study.

Electropalatography is a technique that employs a custom-made artificial palate to measure the contact established between the tongue and the hard palate. This technique is widely used in treatment of articulation disorders and studies of speech. In order to evaluate the accuracy of the electropalate, the device needs to be separated from the volume that usually contains electropalate worn on hard palate. This is done with the use of segmentation techniques. Prior to the segmentation, the registration of the two volumes, one containing the electroplate worn on hard palate, and one containing only hard palate, needs to be done. The registration is a technique of aligning multiple images by geometrical transform. Over the years, many methods for registration have been developed. The following paper describes the method of registration based on sensitivity analysis. Sensitivity analysis is a technique that evaluates the change in the number of pixels with different intensity with a shift of the volumes in different dimensions. Then based on the found optimal shift value, the shift in different dimension of the matrix is made. The technique successfully improves the alignments between two data sets, reducing the number of non-matching pixels. The sensitivity analysis-based registration should be useful in the future improvement of image processing tools that are crucial for the medical imaging.

Lubricin or proteoglycan-4 (PRG-4) is a mucinous glycoprotein lubricating the cartilage and maintaining normal tissue function and cell-homeostasis. Altered O-glycoforms of lubricin has been found in osteoarthritis (OA) synovial fluid (SF). Here, we utilized a Fluorescent Immuno-Lectin Assay (FILA) to measure the levels of lubricin glycoforms in plasma/SF and their potential as biomarkers for disease. Five different lectins were used in the assay: Macrophage Galactose-type lectin (MGL), Sambucus Nigra Agglutinin (SNA), Maackia Amurensis Agglutinin (MAA), Peanut Agglutinin (PNA), and Galectin-3 (Gal-3). Our results showed that the levels of lubricin glycoforms in late-stage knee OA plasma (typically <10 g/ml) are 1-3 order of magnitude lower than in OA SF (typically> 100 g/ml). Furthermore, plasma lubricin glycans displayed higher level of sialylation, while SF derived lubricin displayed higher level of Tn-antigens. In OA patients we found decreased level in plasma of SNA binding lubricin (p=0.0023) compared to controls. This lectin binds 6 linked sialic acid. In addition, we found that lubricin glycoforms correlated both with Body Mass Index (BMI) and age, especially in regards of sialylation as measured by both MAA and SNA. Our data suggest that glycosylation of lubricin is different comparing SF with plasma. Moreover, the glycosylation of plasma lubricin is altered in OA patients compared controls.

ContextCategorization in medicine is used to enhance understanding of a disease or syndrome and apply it to treatment and is based on human clinical experience or theory. Cluster analysis using the K-means algorithm is an unsupervised machine learning method that classifies clusters based on numerical data. The purpose of this study was to classify subjects into clusters using K-means algorithm based on shoulder range of motion (ROM) and identify the characteristics of the clusters. DesignCross-sectional study Methods551 data samples measured in the 5th Size Korea Anthropometric Survey (2003[~]2004) were used. Clustering was performed using the K-means algorithm, and the appropriate number of clusters was determined using the elbow curve and silhouette score. The characteristics of the clusters were analyzed by comparing the average values of shoulder ROM in the clusters. ResultsThe appropriate number of classifications of clusters according to the shoulder ROM was 8. Clusters 1 and 5 had the lowest flexion range, and clusters 7 and 8 had low internal rotation and shoulder horizontal adduction ranges. Clusters 2 and 6 exhibited the highest flexion and overall high flexibility. Clusters 3 and 4 showed moderate flexion ranges but low horizontal adduction ranges. Shoulder movement patterns were classified into a total of 8 clusters according to the shoulder ROM. ConclusionBased on this clustering system, it was possible to identify the pattern of shoulder movement in ordinary people, and it could be used as basic data to identify and treat diseases or syndromes according to the pattern.

The user-operated audiometry (UAud) project aims at introducing an automated system for user-operated audiometric testing into everyday clinical practice. Here, we focus on the Audible Contrast Threshold (ACT) test, which has been proposed as a language-independent alternative to aided speech-in-noise tests. Five distinct user-operated ACT (U-ACT) test candidates were evaluated in terms of performance, reliability, and usability against two established test benchmarks. The study involved 28 participants with diverse hearing and cognitive abilities. The results demonstrated that the primary factor influencing the reliability of test results was the type of task. In terms of usability, the participants reported positive experience with all test candidates, with the Yes/No task resulting in the lowest perceived difficulty and best understanding. Overall, a test candidate with a custom adaptive procedure inspired by audiologists experiences with ACT was chosen for the UAud protocol as a user-operated test of hearing-in-noise perception.

Bioprinting is an emerging tissue engineering method used to generate cell-laden scaffolds with high spatial resolution. Bioprinting parameters, such as pressure, nozzle size, and speed, have a large influence on the quality of the bioprinted construct. Moreover, cell suspension density, cell culture period, and other critical biological parameters directly impact the biological function of the final product. Therefore, an approximation model that can be used to find the values of bioprinting parameters that will result in optimal bioprinted constructs is highly desired. Here, we propose type-1 and type-2 fuzzy systems to handle the uncertainty and imprecision in optimizing the input values. Specifically, we focus on the biological parameters, such as culture period, that can be used to maximize the output value (mineralization volume). To achieve a more accurate approximation, we have compared a type-2 fuzzy system with a type-1 fuzzy system using two levels of uncertainty. We hypothesized that type-2 fuzzy systems may be preferred in biological systems, due to the inherent vagueness and imprecision of the input data. Here, our results demonstrate that the type-2 fuzzy system with a high uncertainty boundary (30%) is superior to type-1 and type-2 with low uncertainty boundary fuzzy systems in the overall output approximation error for bone bioprinting inputs.

Hearing loss is a highly prevalent chronic condition that degrades the quality of life. Although hearing aids provide immediate and efficient benefits to listeners with mild-to-moderate hearing loss, the prevalence of hearing aid use has been low. Consumer wireless earbuds are increasingly being equipped with the ability to amplify external sounds, which can be an affordable alternative to hearing aids. This study compared the amplification performance of non-customized Bluetooth consumer hearables to high-end hearing aids when used by people with mild-to-moderate hearing loss. We found that such a non-customized consumer device significantly enhances the speech recognition of listeners with mild-to-moderate hearing loss, although its performance did not reach the hearing aids. These results determine the extent to which inexpensive and accessible non-customized Bluetooth hearables can help people with mild-to-moderate hearing loss.

Methods based on psychoacoustical forward masking have been proposed to estimate the local compressive growth of the basilar membrane (BM). This results from normal outer hair cells function, which leads to level-dependent amplification of BM vibration. Psychoacoustical methods assume that cochlear processing can be isolated from the response of the overall system, that sensitivity is dominated by the tonotopic location of the probe and that the effect of forward masking is different for on- and off-characteristic frequency (CF) maskers. In the present study, a computational model of the auditory nerve (AN) in combination with signal detection theory was used to test these assumptions. The underlying idea was that, for the BM compression to be estimated using psychoacoustics, enough information should be preserved at the level of the AN, because this forms an information bottleneck in the ascending auditory pathway. The simulated AN responses were quantified in terms of rate and synchrony for different types of AN fibers and CFs. The results show that, when using a low-intensity probe, local activity at the tonotopic location of the probe frequency is the dominant contributor to sensitivity in the healthy auditory system. However, on- and off-CF maskers produced similar forward masking onto the probe, which was mainly encoded by high- and to little extent by medium-spontaneous rate fibers. The simulation results suggested that the estimate of compression based on the behavioral experiments cannot be derived from sensitivity at the level of the AN but may require additional contributions, supporting previous physiological studies.

The COVID-19 pandemic has led to a surge in the design and production of fabric face coverings. There are few published methods which enable mask designers, makers and purchasers to assess the relative filtration ability of mask making materials. Those methods which do exist are prohibitively expensive and difficult to conduct. As a result, mask makers, non-profits, and small-scale designers face difficult decisions when designing face coverings for personal and commercial use. In this paper, we propose a novel method, the Qualitative Filtration Efficiency Assessment (QFEA), for easily and inexpensively comparing the filtration efficiency of common materials. This method provides a highly affordable and readily available way to assess potential mask materials.