Artificial Neural Network for Prediction of Seat-to-Head Frequency Response Function During Whole Body Vibrations in the Fore-and-Aft Direction

Vibrations while driving, regardless of their intensity and shape, have the most obvious effect of reducing driving comfort. Seat-to-head frequency response function (STHT) is a complex relationship resulting from the movement of the head due to the action of excitation on the seat in the form of vibrations in the seat/head interface. In this research, an artificial neural network model was developed, which aims to simulate the STHT function through the body of the subjects based on the data obtained experimentally. The experiments were conducted with twenty healthy male volunteers, who were exposed to single-axis fore-and-aft random broadband vibration. All the results of the experiment were recorded on the basis of which the artificial neural network (ANN) was trained. The developed ANN model has the ability to predict STHT values in the range of trained values both when changing the anthropometric measures of the subjects and changes in the input characteristics of vibrations. The mathematical models based on recurrent neural networks (RNN) used in this paper show with high accuracy STHT values in case there exists prior information about the anthropometric measures of the subjects and the input characteristics of vibrations. The results show that the expensive real-time simulations could be avoided by using reliable neural network models

Efeito de métodos de polimento em laboratório e em consultório na topografia de superfície de materiais de splint oclusal fabricados usando tecnologias digitais convencionais, subtrativas e aditivas

Objective: This study evaluated the polishing properties of the occlusal splint materials obtained using subtractive and additive manufacturing methods with the laboratory-type polishing (LP) and chairside-type polishing (CP) procedures. Material and Methods: Specimens (N=180, n=60 each group) were manufactured using one of the following methods: subtractive manufacturing method (SMM) (M-PM Disc, Merz Dental GmbH), additive manufacturing method (AMM) (Freeprint Splint 2.0, DETAX GmbH & Co. KG), and the conventional manufacturing method (CMM) (Promolux HC, Merz Dental GmbH). Following LP and CP procedures, surface roughness of the specimens was measured using a digital surface profilometer. One representative specimen was selected from each group, and a scanning electron microscope (SEM) image was made. Results: Both the manufacturing method and the polishing procedures significantly affected the results (P<0.01). Interaction terms were also significant (P[removed]Objetivo: Este estudo avaliou as propriedades de polimento dos materiais de splint oclusal obtidos usando métodos de fabricação subtrativos e aditivos com os procedimentos de polimento laboratorial (LP) e polimento em consultório (CP). Material e Métodos: As amostras (N=180, n=60 para cada grupo) foram fabricadas usando um dos seguintes métodos: método de fabricação subtrativo (SMM) (M-PM Disc, Merz Dental GmbH), método de fabricação aditivo (AMM) (Freeprint Splint 2.0, DETAX GmbH & Co. KG) e o método de fabricação convencional (CMM) (Promolux HC, Merz Dental GmbH). Seguindo os procedimentos de LP e CP, a rugosidade da superfície dos espécimes foi medida usando um perfilômetro de superfície digital. Um espécime representativo foi selecionado de cada grupo, e uma imagem de microscópio eletrônico de varredura (SEM) foi obtida. Resultados: Tanto o método de fabricação quanto os procedimentos de polimento afetaram significativamente os resultados (P<0,01). Os termos de interação também foram significativos (P<0,001). Conclusão: Com ambos os métodos de polimento, a rugosidade superficial do grupo AMM foi a maior e a do grupo CMM a menor. Embora o procedimento CP tenha sido mais eficaz do que LP com ambos os métodos, a rugosidade da superfície ficou abaixo do limite de 0,2 μm após ambos os procedimentos de polimento testados

Effects of Different Gas Compositions on the Color Estimations of MAP Packaged Pork Chops

AbstractThis study was conducted to observe effects of different gas compositions on color of pork chops packaged in modified atmospheres. Gaseous compositions used were: MAP1 (75% O2:25% CO2); MAP2 (70% O2:30%CO2) and MAP3 (80% O2:20% CO2). Sensory evaluations of meat color and chemical properties (acid number, peroxide value, aw, pH, TVB-N and TBARs), were carried on the 1st, 5th, 7th, 9th and 12th day of storage. The sensory evaluations of chop color in different MAP compositions are analyzed in relation to storage period, measured chemical properties and instrumental determination of meat color using linear and multivariate linear regression analysis

Insomnia in Patients Seeking Care at an Orofacial Pain Unit

Introduction: Orofacial pain and dysfunction include a broad range of disturbances among which pain and insomnia are some of the most common complaints. Sleep strengthens physiological and psychological resilience and is an absolute requirement for health. Insomnia is a common symptom or sleep disorder, yet data on its prevalence is sparse. Here we extracted data from the insomnia severity index which was part of the web-based interdisciplinary symptom evaluation (WISE) tool given to a large sample of patients seeking care at an orofacial pain unit for analyzing insomnia prevalence in this clinical population.Material and methods: Anonymized data were available from 952 patients who consulted the Orofacial Pain Unit at the Center of Dental Medicine, University of Zurich, Zurich, Switzerland between January 2017 and December 2018. Prevalence data for insomnia stratified by gender and 10 age groups (decades) were calculated. The distribution of four insomnia severity grades was determined, also stratified by age and gender.Results: 952 patients (290 men: 30.5%) with a mean age of 44.8 ± 17.4 years completed a WISE. Three hundred and fifty-two (37.0%) patients with a mean age of 45.8 ± 16.7 years positively responded to a screening question for insomnia and/or hypersomnia. Insomnia was severe in women from the 2nd to 8th decade, ranging from 4.3% (3rd decade) to 14.5% (6th decade), and moderately severe from the 2nd to 9th decade, ranging from 18.8% (6th decade) to 27.8% (2nd decade). In men, severe insomnia was present from the 3rd to 7th decade, ranging from 2.3% (7th decade) to 4.4% (4th decade) and moderately severe insomnia from the 3rd to 7th decade, ranging from 4.6% (7th decade) to 12.2% (5th decade).Conclusions: This is the first study reporting on insomnia in a large sample of patients seeking care at an orofacial pain unit. One in three patients reported some form of sleep disturbances, which for almost half of them was moderate to severe insomnia. The gender ratio was almost equal throughout adulthood, yet younger and older women were more frequently affected and experienced higher insomnia severity than men

Tracking local anesthetic effects using a novel perceptual reference approach

Drug effects of loco-regional anesthetics are commonly measured by unidimensional pain rating scales. These scales require subjects to transform their perceptual correlates of stimulus intensities onto a visual, verbal, or numerical construct that uses a unitless cognitive reference frame. The conceptual understanding and execution of this magnitude estimation task may vary among individuals and populations. To circumvent inherent shortcomings of conventional experimental pain scales, this study used a novel perceptual reference approach to track subjective sensory perceptions during onset of an analgesic nerve block. In 34 male subjects, nociceptive electric stimuli of 1-ms duration were repetitively applied to left (target) and right (reference) mandibular canines every 5 s for 600 s, with a side latency of 1 ms. Stimulus strength to the target canine was programmed to evoke a tolerable pain intensity perception and remained constant at this level throughout the experiment. A dose of 0.6 ml of articaine 4% was submucosally injected at the left mental foramen. Subjects then reported drug effects by adjusting the stimulus strength (in milliamperes) to the reference tooth, so that the perceived intensity in the reference tooth was equi-intense to the target tooth. Pain and stimulus perception offsets were indicated by subjects. Thus, the current approach for matching the sensory experience in one anatomic location after regional anesthesia allows detailed tracking of evolving perceptual changes in another location. This novel perceptual reference approach facilitates direct and accurate quantification of analgesic effects with high temporal resolution. We propose using this method for future experimental investigations of analgesic/anesthetic drug efficac

Midfacial pain

Midfacial pain is not a diagnosis per se but rather describes an anatomical region of pain manifestation of various origins. The midface is built of cavities (nose, sinuses), calcified structures (teeth, bone) and soft tissues (nerves, muscles, mucosa, salivary glands, cartilage, skin). Since midfacial bones form the nose, sinuses and the alveolar ridge containing the upper teeth, the following three specialties are commonly consulted by patients experiencing midfacial pai

Measuring anger in patients experiencing chronic pain - A systematic review

Anger is prevalent in chronic pain and has been associated with pain perception, disability, behavior and treatment outcome. Objectives were (1) to survey in the context of chronic pain the application (and omission) of validated anger self-report instruments, (2) to discuss the instruments found in the context of emotion theories and (3) to identify a possible instrument preference. A systematic search of textbooks and review articles was first performed on validated instruments designed to measure the cognitive, the motivational and the subjective feeling component of anger. Thereafter, a systematic review aimed at finding chronic pain studies from 2005 to 2019 reporting on these instruments. Textbooks and reviews listed 16 validated self-report anger measurement instruments. 28 papers applying four of these were identified and two new instruments were additionally detected. The State-Trait Anger Expression (STAXI) and its precursors were most commonly used. Studies on chronic low back pain patients prevailed. In conclusion, anger in chronic pain patients is reliably measurable at low cost with self-report tools. The STAXI-II qualifies best for this purpose based on its extensive validation history. The majority of instruments lack sufficient theoretical and psychometric adequacy. A more detailed exploration of the cognitive anger component in chronic pain patients in future research is recommended

Das Burning-Mouth-Syndrom

Anhaltendes Brennen im Mundbereich ohne dokumetierbare Ursache kann die Lebensqualität beeinträchtigen und zu frustrierenden Arzt- bzw. Zahnarztbesuchen führen. Die Gründe des primären Mundbrennens sind noch weitgehend unklar und werden erforscht. Wegen der Schmerzlokalisation kommt der Zahnmedizin eine zentrale diagnostische und therapeutische Rolle zu. Der Beitrag beleuchtet das aktuelle Wissen zum Thema und gibt Hinweise zur Behandlung betroffener Patienten

Kiefergelenkbeschwerden – eine biopsychosoziale Umschau

Bei Kiefergelenkbeschwerden besteht die ärztliche Aufgabe darin, die im Vordergrund beklagten somatischen Beschwerden in Zusammenhang mit allfälligen biographischen, psychischen und sozialen Faktoren zu verstehen und daraus therapeutische Optionen abzuleite