Effect of energy renovation and occupants' activities on airborne particle concentrations in Swedish rental apartments.

Exposure to airborne particles causes detrimental health effects, hence their assessment in indoor environments, where people spend most of the time, is important. The influence of energy renovation and occupants' activities on airborne particle concentrations was assessed in seven occupied Swedish residences. Ultrafine particle (UFP, <100 nm) number concentrations, PM2.5 (<2.5 µm) and black carbon (BC, <900 nm) mass concentrations were simultaneously measured inside and outside before, after renovation, and during follow-up. The average indoor UFP number concentrations increased from 6200 (±4070) cm-3 before renovation to 12,700 (±6040) cm-3 during the follow up, as the number of indoor activities doubled. Indoor UFP number concentrations depended mainly on frequency and type of occupants' activities in studied residences (e.g., cooking, candle burning). The average indoor PM2.5 concentration decreased from 8.6 (±5.8) µg m-3 before renovation to 2.5 (±1.3) µg m-3 during follow up, as the activities that generated PM2.5 decreased, and infiltration of outdoor particles could have been decreased due to renovation measures. However, the indication of infiltration decrease during the follow up, assessed on the basis of indoor to outdoor ratios during non-activity times (with no influence of occupants' activities), was not observed after the renovation and should be treated with caution. In this study indoor PM2.5 and BC were influenced by activities and outdoor concentrations. Reduction of exposure to indoor UFP, might be obtained by optimization of kitchen exhaust flows. An improved design of supply air inlets in mechanical exhaust ventilation systems may reduce PM2.5 infiltration. Occupants' logbook records, needed for identification of sources contributing to particle exposure, proved useful but not always accurate compared to technical measurements of activities and UFP concentrations. Development of simple and reliable activity detection systems is needed to complement logbooks and allow accurate assessment of source contribution to particle exposure in homes and associated health effects.

Feasibility of ActivABLES to promote home-based exercise and physical activity of community-dwelling stroke survivors with support from caregivers: A mixed methods study.

BACKGROUND: Technical applications can promote home-based exercise and physical activity of community-dwelling stroke survivors. Caregivers are often able and willing to assist with home-based exercise and physical activity but lack the knowledge and resources to do so. ActivABLES was established to promote home-based exercise and physical activity among community-dwelling stroke survivors, with support from their caregivers. The aim of our study is to investigate the feasibility of ActivABLES in terms of acceptability, demand, implementation and practicality. METHODS: A convergent design of mixed methods research in which quantitative results were combined with personal experiences of a four-week use of ActivABLES by community-dwelling stroke survivors with support from their caregivers. Data collection before, during and after the four-week period included the Berg Balance Scale (BBS), Activities-Specific Balance Confidence Scale (ABC), Timed-Up-and-Go (TUG) and Five Times Sit to Stand Test (5xSST) and data from motion detectors. Semi-structured interviews were conducted with stroke survivors and caregivers after the four-week period. Descriptive statistics were used for quantitative data. Qualitative data was analysed with direct content analysis. Themes were identified related to the domains of feasibility: acceptability, demand, implementation and practicality. Data was integrated by examining any (dis)congruence in the quantitative and qualitative findings. RESULTS: Ten stroke survivors aged 55-79 years participated with their informal caregivers. Functional improvements were shown in BBS (+ 2.5), ABC (+ 0.9), TUG (- 4.2) and 5xSST (- 2.7). More physical activity was detected with motion detectors (stand up/sit down + 2, number of steps + 227, standing + 0.3 h, hours sitting/lying - 0.3 h). The qualitative interviews identified themes for each feasibility domain: (i) acceptability: appreciation, functional improvements, self-initiated activities and expressed potential for future stroke survivors; (2) demand: reported use, interest in further use and need for follow-up; (3) implementation: importance of feedback, variety of exercises and progression of exercises and (4) practicality: need for support and technical problems. The quantitative and qualitative findings converged well with each other and supported the feasibility of ActivABLES. CONCLUSIONS: ActivABLES is feasible and can be a good asset for stroke survivors with slight or moderate disability to use in their homes. Further studies are needed with larger samples.

Developing ActivABLES for community-dwelling stroke survivors using the Medical Research Council framework for complex interventions.

BACKGROUND: Novel technical solutions are called for to promote home-based exercise among community-dwelling stroke survivors supported by their caregivers. Lack of resources and knowledge about how to accomplish it, has been demonstrated. The objective of this study is to describe in detail the development of ActivABLES, a technical intervention to promote home-based exercise and physical activity engagement of community-dwelling stroke survivors with support from their caregivers. METHODS: The technical development process of ActivABLES was guided by the Medical Research Council (MRC) framework for development and evaluation of complex interventions as well as by principles of human-centred design and co-design. The main steps included: (1) Synthesis of evidence supporting the inclusion of balance exercises, mobility and walking exercises and exercises for the upper arm; (2) Implementation of initial user studies with qualitative data collection from individual interviews with stroke survivors, and focus group interviews with caregivers and health professionals; (3) Preliminary testing of eight prototypes with seven stroke survivors and their caregivers. RESULTS: After the preliminary testing of eight prototypes, four prototypes were not further developed whereas four prototypes were modified further. In addition, two new prototypes were developed, leaving six prototypes for further modification: 1) ActivFOAM for balance exercises, 2) WalkingSTARR to facilitate walking, 3) ActivBALL for hand exercises, 4) ActivSTICKS for upper arm exercises, and 5) ActivLAMP and 6) ActivTREE which both give visual feedback on progress of daily exercise and physical activities. ActivFOAM, ActivBALL and ActivSTICKS are all connected to a tablet where exercise instructions are given. All the exercise prototypes can be connected to ActivLAMP and ActivTREE to give feedback on how much exercise the user has done. Settings can be individualised and recommended daily time and/or repetition can easily be changed as the user progresses to higher activity levels. CONCLUSIONS: The development process of ActivABLES was guided by the principles of human-centred design, with iterative testing of future users, and by the MRC framework of complex intervention, with a repeated process of development and testing. This process resulted in six prototypes which are available for feasibility testing among a small group of community-dwelling stroke survivors.

Universal Balance?

In the ActivAbles and STARR projects we are developing interactive training tools for stroke survivors. As our initial user studies pointed to balance being a key ability, one of the developed tools is an interactive balance mat. While balance equipment is common, interactive balancing equipment for persons with poor balance is less common. Equipment exists for persons with good balance (eg. Wii), but most games and exercises are less suited for many stroke survivors. The development process has been done in close collaboration with stroke survivors. We have used both creative workshops and individual iterative testing in the development, and have currently a prototype that is being tested in the home of 12 stroke survivors. This prototype is based on a foam mat which incorporates pressure sensing, and which allows you to see the pressure distribution as you exercise, but also allows you to play music or play different games. The feedback is designed to be inclusive - designs are multimodal (visual and auditory), and the setup is flexible and can easily be adapted. Initial test results show that the overall design is promising and works well (is robust, motivating and used). Problems identified are connected to the fact that we use main stream tablets for feedback, which adds complexity for the user both with interaction and charging. We are currently working on solving these problems, and expect to end up with a balance mat well suited for a wide range of users - not only stroke survivors.

Healthy Indoor Environments: The Need for a Holistic Approach.

Indoor environments have a large impact on health and well-being, so it is important to understand what makes them healthy and sustainable. There is substantial knowledge on individual factors and their effects, though understanding how factors interact and what role occupants play in these interactions (both causative and receptive) is lacking. We aimed to: (i) explore interactions between factors and potential risks if these are not considered from holistic perspective; and (ii) identify components needed to advance research on indoor environments. The paper is based on collaboration between researchers from disciplines covering technical, behavioural, and medical perspectives. Outcomes were identified through literature reviews, discussions and workshops with invited experts and representatives from various stakeholder groups. Four themes emerged and were discussed with an emphasis on occupant health: (a) the bio-psycho-social aspects of health; (b) interaction between occupants, buildings and indoor environment; (c) climate change and its impact on indoor environment quality, thermal comfort and health; and (d) energy efficiency measures and indoor environment. To advance the relevant research, the indoor environment must be considered a dynamic and complex system with multiple interactions. This calls for a transdisciplinary and holistic approach and effective collaboration with various stakeholders.

Development and functional demonstration of a wireless intraoral inductive tongue computer interface for severely disabled persons.

PURPOSE: Individuals with tetraplegia depend on alternative interfaces in order to control computers and other electronic equipment. Current interfaces are often limited in the number of available control commands, and may compromise the social identity of an individual due to their undesirable appearance. The purpose of this study was to implement an alternative computer interface, which was fully embedded into the oral cavity and which provided multiple control commands. METHODS: The development of a wireless, intraoral, inductive tongue computer was described. The interface encompassed a 10-key keypad area and a mouse pad area. This system was embedded wirelessly into the oral cavity of the user. The functionality of the system was demonstrated in two tetraplegic individuals and two able-bodied individuals Results: The system was invisible during use and allowed the user to type on a computer using either the keypad area or the mouse pad. The maximal typing rate was 1.8 s for repetitively typing a correct character with the keypad area and 1.4 s for repetitively typing a correct character with the mouse pad area. CONCLUSION: The results suggest that this inductive tongue computer interface provides an esthetically acceptable and functionally efficient environmental control for a severely disabled user. Implications for Rehabilitation New Design, Implementation and detection methods for intra oral assistive devices. Demonstration of wireless, powering and encapsulation techniques suitable for intra oral embedment of assistive devices. Demonstration of the functionality of a rechargeable and fully embedded intra oral tongue controlled computer input device.

On the tip of the tongue: learning typing and pointing with an intra-oral computer interface.

PURPOSE: To evaluate typing and pointing performance and improvement over time of four able-bodied participants using an intra-oral tongue-computer interface for computer control. BACKGROUND: A physically disabled individual may lack the ability to efficiently control standard computer input devices. There have been several efforts to produce and evaluate interfaces that provide individuals with physical disabilities the possibility to control personal computers. METHOD: Training with the intra-oral tongue-computer interface was performed by playing games over 18 sessions. Skill improvement was measured through typing and pointing exercises at the end of each training session. RESULTS: Typing throughput improved from averages of 2.36 to 5.43 correct words per minute. Pointing throughput improved from averages of 0.47 to 0.85 bits/s. Target tracking performance, measured as relative time on target, improved from averages of 36% to 47%. Path following throughput improved from averages of 0.31 to 0.83 bits/s and decreased to 0.53 bits/s with more difficult tasks. CONCLUSIONS: Learning curves support the notion that the tongue can rapidly learn novel motor tasks. Typing and pointing performance of the tongue-computer interface is comparable to performances of other proficient assistive devices, which makes the tongue a feasible input organ for computer control. IMPLICATIONS FOR REHABILITATION: Intra-oral computer interfaces could provide individuals with severe upper-limb mobility impairments the opportunity to control computers and automatic equipment. Typing and pointing performance of the tongue-computer interface is comparable to performances of other proficient assistive devices, but does not cause fatigue easily and might be invisible to other people, which is highly prioritized by assistive device users. Combination of visual and auditory feedback is vital for a good performance of an intra-oral computer interface and helps to reduce involuntary or erroneous activations.

Features of cortical neuroplasticity associated with multidirectional novel motor skill training: a TMS mapping study.

Given the evidence that the primary motor cortex (MI) consists of subpopulations of upper motor neurons tuned to different directional parameters of a motor movement, this study hypothesized that novel motor skill training involving either a bidirectional or more complex multidirectional tongue-typing movement should produce distinct training-related features of tongue MI neuroplasticity in humans. Novel motor skill training consisted of tongue typing using custom-made intra-oral keypads for 30-min over two consecutive days. The bidirectional keypad consisted of three sensors positioned along the upper palatal midline as a 3 × 1 array, whereas the multidirectional keypad consisted of nine sensors arranged as a 3 × 3 array that was centred along the upper palatal midline. Each sensor corresponded to one letter and participants were asked to type sequences of letters by accurately placing the tongue over the correct sensor. Before and after each training session, excitability of the tongue MI was assessed with transcranial magnetic stimulation (TMS)-motor evoked potentials (MEPs) over 13 motor map sites and TMS-MEP stimulus-response curves were constructed for the first dorsal interosseous (FDI, as an internal control). Tongue-typing performance improved within and across training days for both groups; although bidirectional training displayed greater success. Bidirectional and multidirectional training were associated with increases and decreases in a number of cortical motor map sites from where tongue activity could be evoked, however; multidirectional training was associated with a greater number of cortical motor map sites with increased excitability and a shift in the centre of gravity of the motor map. No effects of training were found on the FDI TMS-MEP stimulus-response curves. This study revealed distinct training-related features of tongue MI neuroplasticity and proposes that a greater amount of functionally related neuronal populations may be 'trained' by the inclusion of different and more complex directional parameters within a novel motor task.

Effects of sensory feedback in intra-oral target selection tasks with the tongue.

PURPOSE: To investigate the effects of visual and tactile intra-oral sensor-position feedback for target selection tasks with the tip of the tongue. METHOD: Target selection tasks were performed using an inductive tongue-computer interface (ITCI). Visual feedback was established by highlighting the area on a visual display corresponding to the activated intra-oral target. Tactile feedback was established using a sensor-border matrix over the sensor plates of the ITCI, which provided sensor-position tactile queues via the user's tongue. Target selection tasks using an on-screen keyboard by controlling the mouse pointer with the ITCI's was also evaluated. RESULTS: Mean target selection rates of 23, 5 and 15 activations per minute were obtained using visual, tactile and "none" feedback techniques in the 3rd training session. On-screen keyboard target selection tasks averaged 10 activations per minute in the 3rd training session. Involuntary activations while speaking or drinking were significantly reduced either through a sensor-matrix or dwell time for sensor activation. CONCLUSIONS: These results provide key design considerations to further increase the typing efficiency of tongue-computer interfaces for individuals with upper-limb mobility impairments.

Tip of the tongue selectivity and motor learning in the palatal area.

This study assessed the ability of the tongue tip to accurately select intraoral targets embedded in an upper palatal tongue-computer interface, using 18 able-bodied volunteers. Four performance measures, based on modifications to Fitts's Law, were determined for three different tongue-computer interface layouts. The layouts differed with respect to number and location of the targets in the palatal interface. Assessment of intraoral target selection speed and accuracy revealed that performance was indeed dependent on the location and distance between the targets. Performances were faster and more accurate for targets located farther away from the base of the tongue in comparison to posterior and medial targets. A regression model was built, which predicted intraoral target selection time based on target location and movement amplitude better than the predicted by using a standard Fitts's Law model. A 30% improvement in the speed and accuracy over three daily practice sessions of 30 min emphasizes the remarkable motor learning abilities of the tongue musculature and provides further evidence that the tongue is useful for operating computer-interface technologies.

Inductive tongue control of powered wheelchairs.

Alternative and effective methods for controlling powered wheelchairs are important to individuals with tetraplegia and similar impairments whom are unable to use the standard joystick. This paper describes a system where tongue movements are used to control a powered wheelchair thus providing users, with high level spinal cord injuries, full control of their wheelchair. The system is based on an inductive tongue control system developed at Center for Sensory-Motor Interaction (SMI), Aalborg University. The system emulates a standard analog joystick in order to interface the wheelchair, thus ensuring that the system works with almost any wheelchair. The total embedment of the tongue interface into the mouth makes the control practically invisible. A fuzzy system combining 8 sensors for directional control allows for multidirectional control of the wheelchair. Preliminary test results show navigation abilities, which are highly competitive when compared to other tongue control system.

Clinical evaluation of wireless inductive tongue computer interface for control of computers and assistive devices.

Typing performance of a full alphabet keyboard and a joystick type of mouse (with on-screen keyboard) provided by a wireless integrated tongue control system (TCS) has been investigated. The speed and accuracy have been measured in a form of a throughput defining the true correct words per minute [cwpm]. Training character sequences were typed in a dedicated interface that provided visual feedback of activated sensors, a map of the alphabet associated, and the task character. Testing sentences were typed in Word, with limited visual feedback, using non-predictive typing (map of characters in alphabetic order associated to sensors) and predictive typing (LetterWise) for TCS keyboard, and non-predictive typing for TCS mouse. Two subjects participated for four and three consecutive days, respectively, two sessions per day. Maximal throughput of 2.94, 2.46, and 2.06, 1.68 [cwpm] were obtained with TCS keyboard by subject 1 and 2 with predictive and non-predictive typing respectively. Maximal throughput of 2.09 and 1.71 [cwpm] was obtained with TCS mouse by subject 1 and 2, respectively. Same experimental protocol has been planned for a larger number of subjects.

TongueWise: Tongue-computer interface software for people with tetraplegia.

Many computer interfaces and assistive devices for people with motor disabilities limit the input dimensionality from user to system, in many cases leading to single switch interfaces where the user can only press one button. This can, either limit the level of direct access to the functionalities of the operating system, or slow down speed of interaction. In this paper we present TongueWise: a software developed for a tongue computer interface that can be activated with the tip of the tongue and that provides direct input that covers most of the standard keyboard and mouse commands.

Character activation time prediction model for tongue-typing: adaptation of Fitts's law.

This paper presents the development of a character activation time prediction model for tongue-typing. This model is based on a modification of Fitts's law that is more suitable for tip-of-tongue selectivity tasks around the palatal area. The model was trained and evaluated with data from tongue-selectivity experiments using an inductive tongue-computer interface. It takes into account the movement amplitude, target position, interactions between them, character disambiguation time and error correction time.

Fully integrated wireless inductive tongue computer interface for disabled people.

This work describes a novel fully integrated inductive tongue computer interface for disabled people. The interface consists of an oral unit placed in the mouth, including inductive sensors, related electronics, a system for wireless transmission and a rechargeable battery. The system is activated using an activation unit placed on the tongue, and incorporates 18 inductive sensors, arranged in both a key area and a mouse-pad area. The system's functionality was demonstrated in a pilot experiment, where a typing rate of up to 70 characters/minute was obtained with an error rate of 3%. Future work will include tests with disabled subjects.

A framework for mouse and keyboard emulation in a tongue control system.

Effective human input devices for computer control are very important to quadriplegics and others with severe disabilities. This paper describes a framework for computer control without need for special PC software or drivers. The framework is based on a tongue control system recently developed at Center for Sensory-Motor Interaction (SMI), Aalborg University. The framework provides emulation of a standard USB keyboard and mouse, and allows tongue control of any computer using standard USB drivers available in all modern operating systems.

Inductive pointing device for tongue control system for computers and assistive devices.

Experimental results for pointing tasks using a tongue control system are reported in this paper. Ten untrained subjects participated in the experiment. Both typing and pointing tasks were performed, in three short-term training sessions, in consecutive days, by each subject. The system provided a key pad (14 sensors) and a mouse pad (10 sensors with joystick functionality) whose placements were interchanged (front, back) in half of the subjects. The pointing tasks consisted of selecting and tracking a target circle (of 50, 75 and 100 pixels diameter) that occurred randomly in each of the 16 positions uniformly distributed along the perimeter of a layout circle of 250 pixels diameter. The throughput was of 0.808 bits per second and the time on target was of 0.164 of the total tracking time. The pads layout, the subjects, the sessions, the target diameters, and the angle of the tracking direction had a statistically significant effect on the two performance measures. Long term training is required to assess the improvement of the user capability.