Comfort Curve Research Articles

Using a convex ostomy appliance to manage peristomal skin complications: introducing Aura Plus Soft Convex.

This article explores convex stoma appliances, introduces Aura Plus Soft Convex (CliniMed) and presents three case studies of its use. Convexity applies pressure to flatten uneven peristomal skin and form an effective adhesive seal, as well as increase protrusion of a poorly spouted stoma. This reduces the risk of leaks and peristomal skin damage, as well as minimising accessory use. Excess pressure can damage the skin, so convexity should be used with caution at the appropriate depth and firmness for the ostomate's body profile and stomal complications. Aura Plus Soft Convex has a soft and flexible baseplate for easy application and adherence, as well as a unique shape, comfort curves and a large adhesive area to reduce creases and leaks. The hydrocolloid contains Manuka honey to promote skin health, and integral belt loops offer additional security. The case studies show how this appliance can restore peristomal skin integrity and relieve stoma-related anxiety; provide gentle support for a flush stoma and a rounded abdomen; and prevent leaks and improve quality of life after years of stoma-related complications.

Using a convex ostomy appliance to manage peristomal skin complications: introducing Aura Plus Soft Convex.

This article explores convex stoma appliances, introduces Aura Plus Soft Convex (CliniMed) and presents three case studies of its use. Convexity applies pressure to flatten uneven peristomal skin and form an effective adhesive seal, as well as increase protrusion of a poorly spouted stoma. This reduces the risk of leaks and peristomal skin damage, as well as minimising accessory use. Excess pressure can damage the skin, so convexity should be used with caution at the appropriate depth and firmness for the ostomate's body profile and stomal complications. Aura Plus Soft Convex has a soft and flexible baseplate for easy application and adherence, as well as a unique shape, comfort curves and a large adhesive area to reduce creases and leaks. The hydrocolloid contains Manuka honey to promote skin health, and integral belt loops offer additional security. The case studies show how this appliance can restore peristomal skin integrity and relieve stoma-related anxiety; provide gentle support for a flush stoma and a rounded abdomen; and prevent leaks and improve quality of life after years of stoma-related complications.

Directions of Modification of the Model of Perception of the Thermal Environment by Patients of Selected Hospital Wards

Patients are different regarding their health conditions, illnesses and ailments, and mobility. These and other factors could affect their specific feelings about the thermal environment. Current methods of predicting thermal sensations were developed based on research on a group of healthy people. Therefore, the use of these methods with patients should be verified. This paper aimed to verify selected thermal comfort models in terms of their reliability to predict the average assessment of thermal conditions in the patient rooms and the percentage of dissatisfied patients. Thermal condition analyses were based on microclimate parameter measurements and extensive questionnaires among patients, done in parallel in the hospital’s patient rooms. The research was carried out in 23 hospitals located in the following provinces in Poland: (Warmińsko-Mazurskie, Kujawsko-Pomorskie, Mazowieckie, Wielkopolskie, Łódzkie, Świętokrzyskie, Lubelskie and Dolnośląskie). Overall, 890 patients from 14 different specialities participated in the research. Actual thermal sensations of patients differed from predictions obtained from selected thermal comfort models. A comparison of the actual thermal sensations with the PMV model indicates the shift of the comfort curve towards cooler rather than neutral conditions. A comparison of the same to the adaptive model predictions indicates that patients had a higher dissatisfaction rate and preferred cooler thermal conditions than predicted. Research findings show that normative models are not fully reliable in predicting patients’ thermal sensations.

Structural Safety Analysis of Cantilever External Shading Components of Buildings under Extreme Wind Environment

The high intensity of solar radiation and long sunshine time in the Turpan area lead to the necessity of sunshade construction. Sunshade components can effectively block direct solar radiation and the secondary heating of buildings. Through the analysis of the importance and sensitivity of sunshade components, it was found that the importance of sunshade components accounts for the largest proportion of multi-parameters, and the sensitivity of sunshade components accounts for about 60% of the total. At the same time, the change in sunshade length has an important influence on the proportion of air conditioning energy consumption and space comfort when the sunshade length reached the 0.6 m–0.8 m range. The energy consumption curve of air conditioning no longer decreased and tended to be horizontal, which showed that a sunshade could effectively reduce the energy consumption of air conditioning, while the PMV comfort curve gradually increased and tended to be horizontal, indicating that a sunshade could effectively improve indoor comfort; therefore, a sunshade could reduce direct solar radiation, reduce the energy consumption of air conditioning and improve indoor thermal comfort. In view of the extremely harsh climate characteristics of Turpan, although Turpan needs to carry out shading design, as a typical wind-sensitive component, the structural safety of the visor under the action of an extreme wind environment is the primary focus of designers. The design requires wind loads as control loads. Based on the ANSYS Workbench platform, this study used the fluid–structure coupling technology to calculate and solve for the wind load stress and strain of a horizontal sunshade and a vertical sunshade in a cantilevered external sunshade of different buildings orientations. In this study, by solving for the maximum principal stress and maximum principal elastic strain under 10 working conditions, the results showed that the maximum principal stress of the sun visor under all working conditions was 0.39 MPa, which is much smaller than the tensile strength of C25 concrete. The calculated maximum principal elastic strain of the sun visor was 0.12 × 10−4, which is much smaller than the maximum strain value of concrete. Therefore, the wind load under this research condition had no great influence on the structural safety of the concrete sunshade, which proves the structural feasibility of the building sunshade member in the Turpan area, and provides a reference for the future practical engineering of cantilever members in the Turpan area.

Machine Learning Methods in Smart Lighting Toward Achieving User Comfort: A Survey

Smart lighting has become a universal smart product solution, with global revenues of up to US <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\$ $ </tex-math></inline-formula> 5.9 billion by 2021. Six main factors drive the technology: light-emitting diode (LED) lighting, sensors, control, analytics, and intelligence. The Internet of things (IoT) concept with the end device, platform, and application layer plays an essential role in optimizing the advantages of LED lighting in the emergence of smart lighting. The ultimate aim of smart lighting research is to introduce low energy efficiency and high user comfort, where the latter is still in the infancy stage. This paper presents a systematic literature review (SLR) from a bird’s eye view covering full-length research topics on smart lighting, including issues, implementation targets, technological solutions, and prospects. In addition to that, this paper also provides a detailed and extensive overview of emerging machine learning techniques as a key solution to overcome complex problems in smart lighting. A comprehensive review of improving user comfort is also presented, such as the methodology and taxonomy of activity recognition as a promising solution and user comfort metrics, including light utilization ratio, unmet comfort ratio, light to comfort ratio, power reduction rate, flickering perception, Kruithof’s comfort curve, correlated color temperature, and relative mean square error. Finally, we discuss in-depth open issues and future challenges in increasing user comfort in smart lighting using activity recognition.

Preliminary Study of Perceived Vibration Quality for Human Hands

&lt;div class="section abstract"&gt;&lt;div class="htmlview paragraph"&gt;A large body of knowledge exists regarding the effects of vibration on human beings; however, the emphasis is generally on the damaging effects of vibration. Very little information has been published regarding the effect of vibration on perceived consumer product quality. The perceived loudness of a product is quantified using the Fletcher-Munson equal loudness curves, but the equivalent curves for perceived vibration amplitude as a function of amplitude and frequency are not readily available. This “vibration quality” information would be valuable in the design and evaluation of many consumer products, including automobiles. Vibration information is used in the automobile design process where targets for steering wheel, seat track, and pedal vibration are common. For this purpose, the vibration information is considered proprietary and is generally applicable to a narrow frequency range. In this investigation, work paralleling the original Fletcher-Munson study is presented. “Equal comfort curves” for vibration were measured and developed for hands grasping a handlebar. A paired-comparison test methodology was used to establish an equivalency of perceived vibration comfort for vibration in a wide range of vibration amplitudes over a wide range of frequencies. The results include preliminary equal comfort curves for hand vibration, preliminary minimum perceivable vibration curves, and recommendations for a test to provide more definitive results.&lt;/div&gt;&lt;/div&gt;

Simulation Study on the Dynamic Ventilation Control of Single Head Roadway in High‐Altitude Mine Based on Thermal Comfort

Dynamic ventilation control based on the concept of thermal comfort is proposed and applied to single head roadway in high‐altitude gold mine in Qinghai. Hourly thermal comfort values are determined for typical working conditions, and a thermal comfort curve is generated. The values are adjusted based on the external environment and the changes in the miners’ thermal comfort. The Fluent software is used to simulate the temperature field and wind speed field of the tunnel roadway at three heights, and the results are used to fit the thermal comfort curve in the roadway. The results show that the thermal comfort is lowest at a roadway height of 1 m and a longitudinal length of 16 m because the wind speed is the highest and the temperature is lowest at these locations. When the dynamic ventilation control is used, the optimal thermal comfort levels can be determined for the locations in the single head roadway.

Retractable membrane ceilings for indoor thermal environment of residential buildings

Indoor thermal environment of residential buildings has attracted considerable attention due to increasing requirements of building performance and dramatical reduction in non-renewable energy. Utilizing new methods to enhance building performance is necessary to achieve low-energy consumption or sustainable buildings. In this study, a retractable membrane ceiling used as part of the second floor in a typical residential building is proposed to address this research topic.The effects of retractable membrane ceiling on indoor thermal environment are composed of temperature distribution, thermal comfort and energy consumption. It is found that temperature distribution and characteristics are spatial and temporal dependent and that performance enhancement with membrane ceiling unfolding is validated compared with membrane ceiling folding, i.e. 3.7 °C and 0.9 °C. To assess thermal comfort, a revised PMV–PPD method is employed to calculate predicted mean vote and predicted percentage of dissatisfied values. The specific values are within comfort ranges during 11:00–18:00 for both folding and unfolding cases. Moreover, thermal comfort curve with respect to membrane unfolding is smooth and wide, which means that the membrane ceiling can ensure smooth indoor environment. For energy consumption, dynamic energy consumption with membrane unfolding is lower than that with membrane folding. The relationships between outdoor air temperature and energy consumption are established on the basis of experimental results. The comparisons between correlation equations again demonstrate that using retractable membrane ceiling is a direct and efficient way to improve thermal performance and control indoor thermal environment.

Comparing the effects of two school workstations on spine positions and mobility, and opinions on the workstations – A 2-year controlled intervention

A wide variety of conventional design workstations are used in schools and workstations have often been described as inappropriate for children's body dimensions. The present study aimed to investigate the effects of saddle chairs and desks with comfort curve for the body on schoolchildren's spine positions and mobility and opinions of workstations compared to conventional workstations. During the first 12-month study period, the number of participants was 98, 48 in the intervention and 50 in the control group. Since the older control group (9th graders, n = 29) decided against participation after the first 12 months, the number of participants in the entire follow-up of 24 months, was 47 (27 intervention and 20 control participants). During the follow-up, the intervention group used new chairs and desks while the controls used conventional workstations. Spine positions and mobility were measured and both groups completed a questionnaire, concerning opinions of workstations. The results indicated that no difference between groups was found when comparing workstation effects on spine positions and mobility during the whole follow-up. Schoolchildren preferred the ergonomic workstations to the conventional workstations during the first year ( p < 0.001), but no difference was seen during the second year. Relevance to industry : The present results indicated that new design workstations had no effects on spine positions compared to conventional workstations. However, some intra-group positive effects were observed among intervention group. Therefore, the authors believe further development of both school workstations and school environment should be encouraged to ensure better long-term back health in children.

The Working Postures Among Schoolchildren—A Controlled Intervention Study on the Effects of Newly Designed Workstations

School workstations are often inappropriate in not offering an optimal sitting posture. The aim of this study was to investigate the effects of individually adjustable saddle-type chairs with wheels and desks with comfort curve and arm support on schoolchildren's working postures compared to conventional workstations. Ninety-seven participants aged 12-16 years were followed for 1 year, 47 at an intervention school and 50 at a control school. Anthropometrics and workstation dimensions were measured and working postures analyzed for a part of each group (n = 21, both groups) by means of video recording at baseline, before new workstations were introduced, and during follow-up. There was a significant increase in upright back (p= .012) and neck (p= .019) postures in the intervention group compared to controls during follow-up. The saddle-type chairs allowed significantly greater trunk-thigh angles (p < .001) among participants than conventional chairs. In schoolchildren, using individually adjustable saddle-type chairs and desks with comfort curve, a better match between workstations and anthropometric dimensions and improved working postures are obtained than using conventional workstations.

OPTIMIZAITON DESIGN METHOD FOR MOTORCYCLE BRAKE HANDLING COMFORT BASED ON HAUSDORFF DISTANCE

To meet the requirements that arise from brake design and client use, an evaluation by a curve that represents the relationship between the handle movements and handle force to handling comfort is implemented. Based on the analysis of braking principle and recognition of design factors affecting handling comfort, a mathematical model for handling comfort is established. As the essence of handling comfort design is a designing comfort curve matching a target curve that is acquired from the design experiences and varying with different client, a Hausdorff distance method is implemented to represent the similarity between the curves and an optimal handling comfort design model is developed. By the application of that model in practical design, an optimal and feasible handling comfort design result is acquired. The difficulty and low design efficiency in handling comfort design are overcome.

Evaluation of Microsoft's Comfort Curve Keyboard

The purpose of this study was to determine whether there were any postural, performance or perceived comfort differences between a conventional straight keyboard and a new ergonomic concept keyboard developed by Microsoft called the Comfort Curve. The concept keyboard was designed to promote more neutral postures in the wrist using a built-in, padded wrist rest to reduce wrist extension and curved keys in alphanumeric section of the keyboard to reduce ulnar deviation. Using a repeated measures design, 26 typists from various occupations randomly used each keyboard for a period of 15 minutes. Wrist postures were measured using electrogoniometers, typing speed and accuracy was measured using typing performance software and discomfort was subjectively measured in the hands, forearms and shoulders and neck. Compared to the conventional straight keyboard, the Comfort Curve keyboard reduced ulnar deviation by 2.2 ° (p &lt; 0.01) and wrist extension by 6.5 ° (p &lt;0.01). There was a small differences in typing speed (50.6 vs 51.8 WPM; p = 0.03) but no differences in accuracy (93.1% vs. 93.5%, p = 0.29) between the Comfort Curve and standard keyboards respectively. Subjective discomfort ratings in all measured body locations were lower with the Comfort Curve keyboard. The results indicate that the concept keyboard achieved its design goal of reducing wrist extension, ulnar deviation and discomfort while not compromising typing speed and accuracy.

An Ergonomic Computer Keyboard for Conventional, Straight Keyboard Users: Ergonomic Research in Generative Product Design

Straight, conventional keyboards are still the most popular design among those shipped with new personal computer sales and standalone keyboard retail sales. Many keyboard users are reluctant to switch to a more ergonomic keyboard – designs that reduce awkward wrist postures. Ergonomic research led to a design of a new keyboard providing more ergonomic benefit to the masses of conventional, straight keyboard users while being equally or even more preferred. The result was a keyboard: Microsoft Comfort Curve ® Keyboard, designed with a subtle split angle of 12° (instead of 24° of traditional ergonomic keyboards), extending the keys' sizes within this split. The design goals were to reduce ulnar deviation and to maintain approachability and typing performance.

Floor serviceability under dynamic loading

Some structures such as floors and tall buildings that meet the code design criteria exhibit unacceptable vibrations relative to the human user. In particular, occupants of long-span floors constructed with open-web joists and light-weight concrete are likely to experience perceptible or annoying vibrations due to normal human activity that is characterized by impact, such as walking, dancing, running, and jumping. Thus, it is important that a serviceability criterion based on human response be used at the design stage to avoid costly problems after the floor is constructed and put into service. Note that human response to vibration is a function of the human body characteristics, the intensity and type of the loading, and the characteristics of the structure such as its frequency, stiffness, mass, and damping. In this paper, a serviceability criterion based on the humanload-structure system is presented. This criterion is the value of the absorbed power (rate of energy dissipation) through the human body as represented by a biomechanical model. The absorbed power levels for the thresholds of perception and annoyance were determined and compared with available human comfort curves. The close agreement demonstrates that absorbed power is a good measure of human response to vibration. To demonstrate the usefulness of absorbed power, floor serviceability was assessed due to walking, heel impact, and dancing. Also, the serviceability of forty-one floors was evaluated using absorbed power and compared to the reported subjective assessments. Absorbed power values correctly predicted the serviceability of thirty-nine of the floors. Furthermore, design curves were produced to assist the engineer in designing serviceable floors.

SOME ASPECTS OF THE INVESTIGATION OF RANDOM VIBRATION INFLUENCE ON RIDE COMFORT

Contemporary vehicles must satisfy high ride comfort criteria. This paper attempts to develop criteria for ride comfort improvement. The highest loading levels have been found to be in the vertical direction and the lowest in lateral direction in passenger cars and trucks. These results have formed the basis for further laboratory and field investigations. An investigation of the human body behaviour under random vibrations is reported in this paper. The research included two phases; biodynamic research and ride comfort investigation. A group of 30 subjects was tested. The influence of broadband random vibrations on the human body was examined through the seat-to-head transmissibility function (STHT). Initially, vertical and fore and aft vibrations were considered. Multi-directional vibration was also investigated. In the biodynamic research, subjects were exposed to 0·55, 1·75 and 2·25 m/s2 r.m.s. vibration levels in the 0·5– 40 Hz frequency domain. The influence of sitting position on human body behaviour under two axial vibrations was also examined. Data analysis showed that the human body behaviour under two-directional random vibrations could not be approximated by superposition of one-directional random vibrations. Non-linearity of the seated human body in the vertical and fore and aft directions was observed. Seat–backrest angle also influenced STHT. In the second phase of experimental research, a new method for the assessment of the influence of narrowband random vibration on the human body was formulated and tested. It included determination of equivalent comfort curves in the vertical and fore and aft directions under one- and two-directional narrowband random vibrations. Equivalent comfort curves for durations of 2·5, 4 and 8 h were determined.

Effects of Different Hematocrit Levels on Glucose Measurements With Handheld Meters for Point-of-Care Testing

c Objectives.—To determine the effects of low, normal, and high hematocrit levels on glucose meter measurements and to assess the clinical risks of hematocrit errors. Design.—Changes in glucose measurements between low and high hematocrit levels were calculated to determine hematocrit effects. The differences between glucose measured with meters and with a plasma glucose method (YSI 2300) also were compared. Setting.—Six handheld glucose meters were assessed in vitro at low (19.1%), normal (38.5%), and high (58.3%) hematocrit levels, and at 6 glucose concentrations ranging from 2.06 mmol/L (37.1 mg/dL) to 30.24 mmol/L (544.7 mg/dL). Results.—Most systems, regardless of the reference to which they were calibrated, demonstrated positive bias at lower hematocrit levels and negative bias at higher hematocrit levels. Low, normal, and high hematocrit levels progressively lowered Precision G and Precision QID glucose measurements. Hematocrit effects on the other systems were more dependent on the glucose concentration. Overall, Accu-Chek Comfort Curve showed the least sensitivity to hematocrit changes, except at the lowest glucose concentration. Conclusions.—We strongly recommend that clinical professionals choose glucose systems carefully and interpret glucose measurements with extreme caution when the patient’s hematocrit value changes, particularly if there is a simultaneous change in glucose level. (Arch Pathol Lab Med. 2000;124:1135‐1140)

Effects of postural and methodological changes on equal comfort contours for whole body, vertical, sinusoidal vibration

The method of adjustment, whereby a subject equates two stimuli by active adjustment of one to match the other, has been used to construct a set of equal comfort curves for both men and women in an unrestrained sitting position, covering the frequency range of 4 to 80 Hz. It has been suggested that differences in posture, methodology and experimental environments have led to large discrepancies between the results of early studies in the field of human sensitivity to whole body vibration. Consequently, the experiment has been repeated, in identical environmental conditions, for male subjects in a standing position and also for male subjects in the unrestrained sitting position used previously but employing a different vibration frequency as the reference. The effects of changed posture and reference vibration stimulus are reported. Comparisons are also made between the results of this study and of other recent investigations.

Equal comfort contours for whole body vertical, pulsed sinusoidal vibration

A method by which subjects equate stimuli by active adjustment (the method of adjustment), has been used to construct a set of equal comfort curves for both men and women in an unrestrained sitting position, covering the frequency range of 4 to 80 Hz. Comparisons are made between the responses of men and women and the results of this study are compared with those of previous investigations where a form of comparative judgement was used. The present recommendations of the International Standards Organization on human vibration exposure are critically compared with the results of this study.