<p>The general aim of the thesis is to answer questions on general and differential aspects of perceived exertion and on the measurement of its intensity variation. Overall perceived exertion is commonly treated as a unidemensional construct. This thesis also explores its multidimensional character. Four empirical studies are summarized (Study I-IV). Psychophysical power functions of perceived exertion obtained with the new improved Borg CR100 (centiMax) scale were found to be consistent with results obtained with absolute magnitude estimation, and with the classical Borg CR10 and RPE scales. Women gave significantly higher perceived exertion scale values than men for the same levels of workload on a bicycle ergometer. This agrees with the fact that they were physically less strong than men. With regard to the measurement of “absolute” levels of intensity, RPE- and CR-scale values were validated by physiological measurements of heart rate and blood lactate. Predicted values of maximal individual performance obtained from psychophysical functions agreed well with actual maximal performance on the bicycle ergometer. This confirms the validity of the RPE and CR scales for measuring perceptual intensity and their value for interindividual comparisons. To study the multidimensional character of perceived exertion, 18 symptoms were measured with a CR scale: in a questionnaire, and in bicycle ergometer work tests. Five factors were extracted for the questionnaire: (1) Muscles and joints; (2) Perceived exertion; (3) Annoyance/lack of motivation; (4) Head/stomach symptoms; and (5) Cardiopulmonary symptoms. Four factors were extracted for the bicycle max test: (1) Physical distress; (2) Central perceived exertion; (3) Annoyance/lack of motivation; (4) Local perceived exertion. The questionnaire is suggested for clinical use to let patients express a variety of symptoms. The thesis also resulted in improvements of the Borg CR100 scale. An extended use of the scale is recommended.</p>

The general aim of the thesis is to answer questions on general and differential aspects of perceived exertion and on the measurement of its intensity variation. Overall perceived exertion is commonly treated as a unidemensional construct. This thesis also explores its multidimensional character. Four empirical studies are summarized (Study I-IV). Psychophysical power functions of perceived exertion obtained with the new improved Borg CR100 (centiMax) scale were found to be consistent with results obtained with absolute magnitude estimation, and with the classical Borg CR10 and RPE scales. Women gave significantly higher perceived exertion scale values than men for the same levels of workload on a bicycle ergometer. This agrees with the fact that they were physically less strong than men. With regard to the measurement of “absolute” levels of intensity, RPE- and CR-scale values were validated by physiological measurements of heart rate and blood lactate. Predicted values of maximal individual performance obtained from psychophysical functions agreed well with actual maximal performance on the bicycle ergometer. This confirms the validity of the RPE and CR scales for measuring perceptual intensity and their value for interindividual comparisons. To study the multidimensional character of perceived exertion, 18 symptoms were measured with a CR scale: in a questionnaire, and in bicycle ergometer work tests. Five factors were extracted for the questionnaire: (1) Muscles and joints; (2) Perceived exertion; (3) Annoyance/lack of motivation; (4) Head/stomach symptoms; and (5) Cardiopulmonary symptoms. Four factors were extracted for the bicycle max test: (1) Physical distress; (2) Central perceived exertion; (3) Annoyance/lack of motivation; (4) Local perceived exertion. The questionnaire is suggested for clinical use to let patients express a variety of symptoms. The thesis also resulted in improvements of the Borg CR100 scale. An extended use of the scale is recommended.

A Visual Analogue Scale (VAS) e a escala Category-Ratio (CR10) foram aplicadas para mensurar a dor em pacientes com Disfunções Temporomandibulares (DTMs) em dois estudos. No primeiro estudo, em 35 pacientes (Grupo I) foram aplicadas uma versão modificada da escala CR10 em português e a VAS para mensurar a dor espontânea, durante função orofacial e durante palpação antes e após tratamento odontológico. A modificação na CR10 consistiu em um desmembramento das categorias verbais e da escala numérica apresentadas cada uma delas em única coluna em mesma folha. Os coeficientes de correlação de Pearson entre as pontuações da VAS e da CR10 foram 0,85 antes do tratamento odontológico e 0,9 após o tratamento, indicando alta validade de critério. A associação entre os valores numéricos e as categorias verbais da Escala CR10 Modificada mostrou diferenças em relação ao que é proposto na escala original. As categorias: “Moderado", “Forte" e “Muito Forte" foram associadas a valores superiores aos originais. O segundo estudo foi planejado para investigar se essas discrepâncias nas associações das categorias com os seus valores numéricos eram replicáveis e verificar se não dependiam da forma de apresentação da escala CR10 modificada. Para isso, as escalas foram aplicadas para medir dor em duas novas amostras de pacientes com DTMs antes do tratamento odontológico. A CR10 com nova modificação e a VAS foram aplicadas à primeira amostra (Grupo II , n=23 pacientes). A modificação na CR10 consistiu na apresentação primeiro da escala numérica em uma coluna seguida pela apresentação das categorias verbais em três colunas. A CR10 original e a VAS foram aplicadas à segunda amostra (Grupo III, n=17 pacientes). Os coeficientes de correlação de Pearson foram 0,9 para o Grupo II e 0,8 para o Grupo III, indicando também alta validade de critério. Assim como no primeiro estudo, na escala CR10, as categorias verbais: “Moderado", “Forte" e “Muito Forte" foram associadas na escala numérica a valores superiores aos propostos na escala original Em ambos estudos, a escala CR10 foi a mais bem avaliada pelos pacientes, segundo a facilidade de compreensão das instruções e a adequação para o registro da dor. Evidencia-se a necessidade de mais estudos para validar a escala CR10 para a língua portuguesa para determinar com precisão a associação das categorias verbais aos valores numéricos. / Visual Analogue Scale (VAS) and Category-Ratio Scale (CR10) were applied to measure pain in patients with Temporomandibular Disorders (TMDs). In the first study, a modified version of CR10 translated to Portuguese and VAS were applied to measure spontaneous pain, functional pain and pain by touch after and before dentistry treatment in 35 patients (Group I). The CR10 modification consisted of presenting the verbal categories and the numerical scale in separated columns in a sheet. Coefficients of Pearson’s correlation between VAS and CR10 scores were .85 and .90 respectively before and after treatment, indicating a high criterion validation. The association of numerical values and verbal categories of Modified CR10 scale were different from the original CR10. The verbal expressions “moderate", “strong" and “very strong" were attached to higher values. In the second study we investigated if these discrepancies in attaching the verbal categories to the numerical scale were replicable and if they were not an artifact of the way of presenting the modified CR10 scale. To check these topics, the scales were applied to measure pain in two new samples of patients with TMD before dentistry treatment. A new modified version of the CR10 scale and the VAS were applied to the first sample (Group II, n=23 patients). This modification in CR10 scale consisted of presenting first the numerical scale in separate column, and then the verbal categories distributed in three columns. The original CR10 and VAS were applied to the second sample (Group III, n=17 patients). Coefficients of Pearsons correlation between CR10 and VAS were .9 for Group II and .8 for Group III, indicating also high criterion validation. As indicated in the first study, some verbal categories were attached to the numerical scale at higher values than those ones in the original scale. In both studies,, most patients judged the CR10 easier to be understood and more adequate to measure pain than VAS. There is evidence of the necessity of more studies to validate CR10 to Portuguese to determine with precision the association of the verbal categories to the numeric values.

O objetivo geral deste estudo foi escalonar os diferentes tipos de dor, comparativamente entre si, por meio de diferentes métodos psicofísicos e diferentes amostras. Os objetivos específicos foram: comparar o escalonamento dos diferentes tipos de dor entre as diferentes amostras; comparar as escalas derivadas de julgamentos ordinais com as escalas derivadas dos julgamentos de razão; verificar por meio da comparação entre as estimativas de magnitudes e as estimativas de categorias se o contínuo intensidade de dor tem características protéticas ou metatéticas; verificar se a variabilidade das estimativas de magnitudes, de categorias e de comprimento de linhas, é uma função linear das médias geométricas dessas estimativas, ou seja, seguem a Lei de Ekman; validar a escala de razão derivada para o contínuo não métrico de intensidade dos diferentes tipos de dor por meio do método de emparelhamento intermodal; verificar se a variabilidade das estimativas de categorias expandidas aumenta linearmente em função do aumento das estimativas de categorias, tal como ocorre com as estimativas de magnitude; verificar se as ordenações dos diferentes tipos de dor derivadas dos respectivos métodos psicofísicos são similares entre si. Para atingir os objetivos foram realizados 3 experimentos, cada experimento utilizou diferentes métodos psicofísicos: Experimento 1 - Comparação entre os métodos psicofísicos escalares de estimação de magnitude, estimação de categorias e estimação de postos; Experimento 2 - Validação da escala de razão dos diferentes tipos de dor por meio do método de estimação de magnitude e de emparelhamento intermodal com a modalidade de resposta comprimento de linhas; Experimento 3 - Comparação entre os métodos psicofísicos escalares de estimação de magnitude e estimação de categorias expandidas. Participaram do estudo 90 pacientes ambulatoriais de diferentes clínicas, 90 médicos e 90 enfermeiros, sendo 30 de cada grupo que participaram de cada Experimento. Os participantes avaliaram, de acordo com cada método psicofísico, o grau de intensidade de dor, comparativamente entre 20 diferentes tipos de dor. Os resultados foram: 1)A Dor no Câncer, a Dor por Infarto do Miocárdio, a Dor por Cólica Renal, a Dor por Queimadura e a Dor no Parto foram considerados os tipos de dor de maior intensidade, independente do método psicofísico utilizado ou da amostra estudada; 2) Há divergências na percepção das intensidades de alguns tipos de dor, estas divergências foram observadas principalmente entre profissionais e pacientes (médicos-pacientes, enfermeiros-pacientes); 3)As ordenações de posições da intensidade dos diferentes tipos de dor, comparando os diferentes métodos psicofísicos utilizados, resultaram em níveis de concordância significativa; 4)O contínuo não métrico de intensidade dos diferentes tipos de dor, possui características protéticas, ou seja, a percepção da intensidade de um tipo de dor aumenta à medida que se percebe esta com maior intensidade; 5)A variabilidade das respostas dos sujeitos (estimação de magnitudes) foi maior quanto mais intenso foram julgados os diferentes tipos de dor, ou seja, segue a Lei de Ekman; 6)A relação entre as estimativas de magnitudes e as estimativas de emparelhamento de comprimento de linhas é uma função de potência e a escala dos diferentes tipos de dor é válida, estável e consistente. / The general aim of this study was to scale the different types of pain comparatively, by means of various psychophysical methods and different samples. The specific aims were: to compare the scaling of the different types of pain between the different samples; to compare the derived scales of ordinal judgments with the derived scales of ratio judgments; to verify them by comparing between the magnitude estimates and the category estimates whether the continual pain intensity had prothetic or metathetic characteristics; to verify the variability of the magnitude estimates, line-length categories and the linear functions of the geometric means of these estimates, or rather, according to Ekman\'s Law; to validate the ratio scale derived from the non-metric continual of the different types of pain intensities by means of the cross-modal matching; to verify whether the variability of the expanded category estimates increases linearly in function of the increase of the category estimates, as it occurs with the magnitude estimates; to verify whether the rank order of the different types of pain derived from the respective psychophysical methods are similar to each other. In order to achieve these goals three experiments were performed, each utilizing different psychophysical methods: Experiment 1 - Comparison among the psychophysical scaling methods of magnitude estimations, category estimations and rank order estimations; Experiment 2 - The ratio scale validation for the different types of pain utilizing line-lengths response modality; Experiment 3 - A comparison between the psychophysical scaling methods of magnitude estimations and expanded category estimations. The study was comprised of 90 outpatients from various specialty clinics, 90 physicians and 90 nurses, in which there were 30 subjects in each group for each of the experiments. The participants assessed the degree of pain intensity among the 20 different types according to each psychophysical method. The results were: 1) A Cancer Pain, Myocardium Infarct Pain, Renal Colic, Burn Injury Pain, and Childbirth Labor Pain were regarded as the pains of greater intensity, regardless of the psychophysical method utilized or the studied sample; 2) it has divergences in the perception of the intensities of some types of pain, these divergences had been mainly evidenced between professionals and patients (doctors-patients, nurses-patients); 3)A the rank order of pain intensity for the different types of pain, comparing the different psychophysical methods used resulted in levels of significant concordance; 4) A the non-metric continual of the pain intensity for the different types possesses prothetic characteristics, that is, the perception of one type of pain intensity increases as it is perceived with greater intensity; 5) A the variability of the subjects\' responses (magnitude estimations) was greater, the more the different types of pain were judged, or rather, it fallows Ekman\'s Law; 6) A the relation between the magnitude estimates and the cross modal matching estimates of the line-lengths is a power function, and the scale for the different types of pain is valid, stable and consistent.

A Visual Analogue Scale (VAS) e a escala Category-Ratio (CR10) foram aplicadas para mensurar a dor em pacientes com Disfunções Temporomandibulares (DTMs) em dois estudos. No primeiro estudo, em 35 pacientes (Grupo I) foram aplicadas uma versão modificada da escala CR10 em português e a VAS para mensurar a dor espontânea, durante função orofacial e durante palpação antes e após tratamento odontológico. A modificação na CR10 consistiu em um desmembramento das categorias verbais e da escala numérica apresentadas cada uma delas em única coluna em mesma folha. Os coeficientes de correlação de Pearson entre as pontuações da VAS e da CR10 foram 0,85 antes do tratamento odontológico e 0,9 após o tratamento, indicando alta validade de critério. A associação entre os valores numéricos e as categorias verbais da Escala CR10 Modificada mostrou diferenças em relação ao que é proposto na escala original. As categorias: “Moderado”, “Forte” e “Muito Forte” foram associadas a valores superiores aos originais. O segundo estudo foi planejado para investigar se essas discrepâncias nas associações das categorias com os seus valores numéricos eram replicáveis e verificar se não dependiam da forma de apresentação da escala CR10 modificada. Para isso, as escalas foram aplicadas para medir dor em duas novas amostras de pacientes com DTMs antes do tratamento odontológico. A CR10 com nova modificação e a VAS foram aplicadas à primeira amostra (Grupo II , n=23 pacientes). A modificação na CR10 consistiu na apresentação primeiro da escala numérica em uma coluna seguida pela apresentação das categorias verbais em três colunas. A CR10 original e a VAS foram aplicadas à segunda amostra (Grupo III, n=17 pacientes). Os coeficientes de correlação de Pearson foram 0,9 para o Grupo II e 0,8 para o Grupo III, indicando também alta validade de critério. Assim como no primeiro estudo, na escala CR10, as categorias verbais: “Moderado”, “Forte” e “Muito Forte” foram associadas na escala numérica a valores superiores aos propostos na escala original Em ambos estudos, a escala CR10 foi a mais bem avaliada pelos pacientes, segundo a facilidade de compreensão das instruções e a adequação para o registro da dor. Evidencia-se a necessidade de mais estudos para validar a escala CR10 para a língua portuguesa para determinar com precisão a associação das categorias verbais aos valores numéricos. / Visual Analogue Scale (VAS) and Category-Ratio Scale (CR10) were applied to measure pain in patients with Temporomandibular Disorders (TMDs). In the first study, a modified version of CR10 translated to Portuguese and VAS were applied to measure spontaneous pain, functional pain and pain by touch after and before dentistry treatment in 35 patients (Group I). The CR10 modification consisted of presenting the verbal categories and the numerical scale in separated columns in a sheet. Coefficients of Pearson’s correlation between VAS and CR10 scores were .85 and .90 respectively before and after treatment, indicating a high criterion validation. The association of numerical values and verbal categories of Modified CR10 scale were different from the original CR10. The verbal expressions “moderate”, “strong” and “very strong” were attached to higher values. In the second study we investigated if these discrepancies in attaching the verbal categories to the numerical scale were replicable and if they were not an artifact of the way of presenting the modified CR10 scale. To check these topics, the scales were applied to measure pain in two new samples of patients with TMD before dentistry treatment. A new modified version of the CR10 scale and the VAS were applied to the first sample (Group II, n=23 patients). This modification in CR10 scale consisted of presenting first the numerical scale in separate column, and then the verbal categories distributed in three columns. The original CR10 and VAS were applied to the second sample (Group III, n=17 patients). Coefficients of Pearsons correlation between CR10 and VAS were .9 for Group II and .8 for Group III, indicating also high criterion validation. As indicated in the first study, some verbal categories were attached to the numerical scale at higher values than those ones in the original scale. In both studies,, most patients judged the CR10 easier to be understood and more adequate to measure pain than VAS. There is evidence of the necessity of more studies to validate CR10 to Portuguese to determine with precision the association of the verbal categories to the numeric values.

O objetivo geral deste estudo foi escalonar os diferentes tipos de dor, comparativamente entre si, por meio de diferentes métodos psicofísicos e diferentes amostras. Os objetivos específicos foram: comparar o escalonamento dos diferentes tipos de dor entre as diferentes amostras; comparar as escalas derivadas de julgamentos ordinais com as escalas derivadas dos julgamentos de razão; verificar por meio da comparação entre as estimativas de magnitudes e as estimativas de categorias se o contínuo intensidade de dor tem características protéticas ou metatéticas; verificar se a variabilidade das estimativas de magnitudes, de categorias e de comprimento de linhas, é uma função linear das médias geométricas dessas estimativas, ou seja, seguem a Lei de Ekman; validar a escala de razão derivada para o contínuo não métrico de intensidade dos diferentes tipos de dor por meio do método de emparelhamento intermodal; verificar se a variabilidade das estimativas de categorias expandidas aumenta linearmente em função do aumento das estimativas de categorias, tal como ocorre com as estimativas de magnitude; verificar se as ordenações dos diferentes tipos de dor derivadas dos respectivos métodos psicofísicos são similares entre si. Para atingir os objetivos foram realizados 3 experimentos, cada experimento utilizou diferentes métodos psicofísicos: Experimento 1 - Comparação entre os métodos psicofísicos escalares de estimação de magnitude, estimação de categorias e estimação de postos; Experimento 2 - Validação da escala de razão dos diferentes tipos de dor por meio do método de estimação de magnitude e de emparelhamento intermodal com a modalidade de resposta comprimento de linhas; Experimento 3 - Comparação entre os métodos psicofísicos escalares de estimação de magnitude e estimação de categorias expandidas. Participaram do estudo 90 pacientes ambulatoriais de diferentes clínicas, 90 médicos e 90 enfermeiros, sendo 30 de cada grupo que participaram de cada Experimento. Os participantes avaliaram, de acordo com cada método psicofísico, o grau de intensidade de dor, comparativamente entre 20 diferentes tipos de dor. Os resultados foram: 1)A Dor no Câncer, a Dor por Infarto do Miocárdio, a Dor por Cólica Renal, a Dor por Queimadura e a Dor no Parto foram considerados os tipos de dor de maior intensidade, independente do método psicofísico utilizado ou da amostra estudada; 2) Há divergências na percepção das intensidades de alguns tipos de dor, estas divergências foram observadas principalmente entre profissionais e pacientes (médicos-pacientes, enfermeiros-pacientes); 3)As ordenações de posições da intensidade dos diferentes tipos de dor, comparando os diferentes métodos psicofísicos utilizados, resultaram em níveis de concordância significativa; 4)O contínuo não métrico de intensidade dos diferentes tipos de dor, possui características protéticas, ou seja, a percepção da intensidade de um tipo de dor aumenta à medida que se percebe esta com maior intensidade; 5)A variabilidade das respostas dos sujeitos (estimação de magnitudes) foi maior quanto mais intenso foram julgados os diferentes tipos de dor, ou seja, segue a Lei de Ekman; 6)A relação entre as estimativas de magnitudes e as estimativas de emparelhamento de comprimento de linhas é uma função de potência e a escala dos diferentes tipos de dor é válida, estável e consistente. / The general aim of this study was to scale the different types of pain comparatively, by means of various psychophysical methods and different samples. The specific aims were: to compare the scaling of the different types of pain between the different samples; to compare the derived scales of ordinal judgments with the derived scales of ratio judgments; to verify them by comparing between the magnitude estimates and the category estimates whether the continual pain intensity had prothetic or metathetic characteristics; to verify the variability of the magnitude estimates, line-length categories and the linear functions of the geometric means of these estimates, or rather, according to Ekman\'s Law; to validate the ratio scale derived from the non-metric continual of the different types of pain intensities by means of the cross-modal matching; to verify whether the variability of the expanded category estimates increases linearly in function of the increase of the category estimates, as it occurs with the magnitude estimates; to verify whether the rank order of the different types of pain derived from the respective psychophysical methods are similar to each other. In order to achieve these goals three experiments were performed, each utilizing different psychophysical methods: Experiment 1 - Comparison among the psychophysical scaling methods of magnitude estimations, category estimations and rank order estimations; Experiment 2 - The ratio scale validation for the different types of pain utilizing line-lengths response modality; Experiment 3 - A comparison between the psychophysical scaling methods of magnitude estimations and expanded category estimations. The study was comprised of 90 outpatients from various specialty clinics, 90 physicians and 90 nurses, in which there were 30 subjects in each group for each of the experiments. The participants assessed the degree of pain intensity among the 20 different types according to each psychophysical method. The results were: 1) A Cancer Pain, Myocardium Infarct Pain, Renal Colic, Burn Injury Pain, and Childbirth Labor Pain were regarded as the pains of greater intensity, regardless of the psychophysical method utilized or the studied sample; 2) it has divergences in the perception of the intensities of some types of pain, these divergences had been mainly evidenced between professionals and patients (doctors-patients, nurses-patients); 3)A the rank order of pain intensity for the different types of pain, comparing the different psychophysical methods used resulted in levels of significant concordance; 4) A the non-metric continual of the pain intensity for the different types possesses prothetic characteristics, that is, the perception of one type of pain intensity increases as it is perceived with greater intensity; 5) A the variability of the subjects\' responses (magnitude estimations) was greater, the more the different types of pain were judged, or rather, it fallows Ekman\'s Law; 6) A the relation between the magnitude estimates and the cross modal matching estimates of the line-lengths is a power function, and the scale for the different types of pain is valid, stable and consistent.

There is an excessive demand for the rehabilitation of frame type reinforced concrete (RC) buildings which do not satisfy current earthquake code provisions. Therefore, it is imperative to develop user-friendly seismic strengthening methodologies which do not necessitate the evacuation of building during rehabilitation period. In this study, it was aimed to strengthen the brick infill walls by means of diagonal Carbon Fiber-Reinforced Polymer (CFRP) fabrics and to integrate them with the existing structural frame in order to form a new lateral load resisting system. The possible effects of height to width (aspect) ratio of the infill walls and scale of the frame test specimens on the overall behavior attained by the developed rehabilitation methodology were investigated. The experimental part of the study was carried out in two steps. In the first step, ten individual panel specimens were tested in order to understand the behavior of strengthened/non-strengthened masonry walls under diagonal earthquake loads. And in the second step, the tests of eight 1/3 and four 1/2 scaled one-bay, two-story RC frames having two different aspect ratios were performed to determine design details. The experimental results were revealed in terms of lateral stiffness, strength, drift and energy dissipation characteristics of the specimens. In the analytical part, an equivalent strut and tie approach was used for modeling the strengthened/non-strengthened infill walls of the frames. The predicted pushover responses of the frame models were compared with the test results. The design criteria required for the aforementioned strengthening methodology was developed referring these analytical results.

Sleep is a basic need as important as physical fitness and good nutrition. Without enough sleep, we will create a sleep debt and experience sleepiness. Sleepiness can be defined as the inability to stay awake, a condition that has become a health problem in our 24-hour-7-day-a-week society. Estimates suggest that up to one-third of the population suffers from excessive sleepiness. Among other interactions, sleepiness affects our performance, increasing the risk of being involved in accidents. A considerable portion of work related accidents and injuries are related to sleepiness resulting in large costs for the individuals and society. Professional drivers are one example of workers who are at risk of sleepiness related accidents. Up to 40% of heavy truck accidents could be related to sleepiness. A better knowledge about reliable indicators and predictors of sleepiness is important in preventing sleepiness related accidents. This thesis investigates both objective and subjective indicators of sleepiness, how these relate to each other, and how their pattern changes over time. The indicators investigated were electroencephalography, heart rate variability, simple reaction time, head movement, and subjective ratings of sleepiness (Study I-IV). In Study V, a questionnaire study was conducted with professional drivers in northern Sweden. This study mainly deals with predictors of sleepiness. When subjects were sleep deprived both objective and subjective ratings indicated a rapid increase in sleepiness during the first hour of the test followed by a levelling off. This change in pattern was evident for all the indicators except heart rate and heart rate variability. On the other hand, HRV was correlated with the increase of EEG parameters during the post-test sleep period. The changes in pattern of the indicators included in the thesis are analysed in the perspective of temporal patterns and relationships. Of the tested indicators, a subjective rating of sleepiness with CR-10 was considered to be the most reliable indicator of sleepiness. Of the investigated predictors of sleepiness, prior sleep habits were found to be strongly associated to sleepiness and the sleepiness related symptoms while driving. The influences of driving conditions and individual characteristics on sleepiness while driving were lower. A multidisciplinary approach when investigating and implementing indicators and predictors of sleepiness is important. In addition to their actual relations to the development of sleepiness, factors such as technical and practical limitations, work, and individual and situational needs must be taken into account.