Interaction with touchscreen smartphones in patients with essential tremor and healthy individuals

INTRODUCTION

Smartphone use in biomedical research is becoming more prevalent in different clinical settings. We performed a pilot study to obtain information on smartphone use by patients with essential tremor (ET) and healthy controls, with a view to determining whether performance of touchscreen tasks is different between these groups and describing touchscreen interaction factors.

METHOD

A total of 31 patients with ET and 40 sex- and age-matched healthy controls completed a descriptive questionnaire about the use of smartphones. Participants subsequently interacted with an under-development Android application, and performed 4 tests evaluating typical touchscreen interaction gestures; each test was performed 5 times.

RESULT

The type of smartphone use and touchscreen interaction were not significantly different between patients and controls. Age and frequency of smartphone use are key factors in touchscreen interaction.

CONCLUSION

Our results support the use of smartphone touchscreens for research into ET, although further studies are required.

Interaction with touchscreen smartphones in patients with essential tremor and healthy individuals

INTRODUCTION

Smartphones use in biomedical research is becoming more prevalent in different clinical settings. We performed a pilot study to obtain information on smartphone use by patients with essential tremor (ET) and healthy controls, with a view to determining whether performance of touchscreen tasks is different between these groups and describing touchscreen interaction factors.

METHOD

A total of 31 patients with ET and 40 sex- and age-matched healthy controls completed a descriptive questionnaire about the use of smartphones. Participants subsequently interacted with an under-development Android application, and performed 4 tests evaluating typical touchscreen interaction gestures; each test was performed 5 times.

RESULT

The type of smartphone use and touchscreen interaction were not significantly different between patients and controls. Age and frequency of smartphone use are key factors in touchscreen interaction.

CONCLUSION

Our results support the use of smartphone touchscreens for research into ET, although further studies are required.

A computational knowledge-based model for emulating human performance in the Iowa Gambling Task

A new computational knowledge-based model for emulating human performance in decision making tasks is proposed. This model is mainly based on the knowledge acquired through past experience, the knowledge extracted from the environment and the relationships between the concepts that represent these two kinds of knowledge. The proposed model divides the decision making process into two phases. The first phase lies in the estimation of the decision outcomes using a net of concepts. In the second phase, the proposed model uses a value function to score each possible alternative. The design of the model focuses on some psychological and neurophysiological evidence from current research. In order to validate the model, it is compared with other widely used models that implement different theories of decision making under risk and uncertainty. The model comparison is centered on a well defined task, the Iowa Gambling Task, used in several psychological experiments. The comparison applies an evaluation method based on the optimization of each model in order to emulate human performance individually starting both the participant and the model from the same environmentally available information. The results show that the performance of the proposed model is quantitatively better than the other compared models. Besides, using relevant concepts extracted from interviews with the participants increases the performance of the proposed model.

An asynchronous BMI system for online single-trial detection of movement intention

This paper presents an approach for an asynchronous BMI proposed as a switching part of a tremor suppression system developed for real-time continuous conditions. The main purpose of this BMI-switch is to anticipate the execution of self-initiated movements performed after relatively long periods of inactivity. The performance indicators used for the detector validation are specially suited for the continuous characteristic of the paradigm used and it is demonstrated that our ERD-based bayesian classifier solution is a reliable option, detecting a high rate of positive cases and generating very few false positives during long intervals of inactivity. The subjects analyzed for our detector validation were patients with neurological tremor caused by different pathologies in order to assure the adaptability of our system.

[Percutaneous valvuloplasty in congenital aortic valve stenosis]

PURPOSE

To show the initial experience of Institute of Cardiology of Rio Grande do Sul in the treatment of congenital valvular aortic stenosis with percutaneous balloon aortic valvuloplasty.

METHODS

Twenty four patients were submitted to the procedure, 14 males and 10 females. The mean age 7 years (4 days-17 years). Four patients were aged below 30 days and three patients had previous surgical valvuloplasty. The percutaneous balloon aortic valvuloplasty were made the retrograde approach in all patients.

RESULTS

The peak systolic pressure gradient was reduced from 65.96 +/- 22.68 to 27.08 +/- 18.74 mmHg. The procedure resulted in aortic regurgitation in seven patients and worsened aortic regurgitation in two patients. One patient had cardiac arrest that was reverted by cardiopulmonary resuscitation, this patient had hospital discharge without sequel. Five patients had acute femoral artery thrombosis, and hemorrhage in the site of puncture happened in one patient.

CONCLUSION

The percutaneous balloon aortic valvuloplasty results in effective reduction of the peak systolic pressure gradient, it is a save and effective therapy in patients with congenital valvular aortic stenosis. Further evaluation of the long term results are necessary for definitive conclusions.

Luminol luminescence induced by 2,2'-Azo-bis(2-amidinopropane) thermolysis

2,2'-Azo-bis(2-amidinopropane) thermolysis induces luminol luminescence. The luminescence intensity is quenched by SOD, catalase, Trolox and human blood serum. However, the time course of the light intensity profile is different for the different additives. In particular, the quenching efficiency of Trolox and human blood serum decreases with time after addition. Double quenching experiments show that SOD and Trolox are not competitive quenchers, while a simple competition can be established between Trolox and human blood serum in trapping a common intermediate. From the kinetic analysis of the data it is concluded that, at least at low additive concentrations, Trolox scavenges a luminol derived radical. Higher concentrations of Trolox or human blood serum produce induction times that are proportional to the additives concentrations. The possibility of employing luminol luminescence in the evaluation of TRAP levels and the capacity of biological samples to scavenge free radicals is discussed.