Responses of human sensory characteristics to 532 nm pulse laser stimuli.

BACKGROUND: Lasers are advantageous in some applications to stimulate a small target area and is used in various fields such as optogenetic, photoimmunological and neurophysiological studies. OBJECTIVE: This study aims to implement a non-contact sense of touch without damaging biological tissues using laser. METHODS: Various laser parameters were utilized in safety range to induce a sense of touch and investigate the human responses. With heat distribution simulation, the amount of changes in the temperature and the tendency in laser parameters of sensory stimulation were analyzed. RESULTS: The results showed the identified tactile responses in safety range with various laser parameters and temperature distribution for the laser stimulus was obtained through the simulation. CONCLUSIONS: This study can be applied to the areas of sensory receptor stimulation, neurophysiology and clinical medicine.

Study of somesthesis according to change in pulse diode laser parameters.

Laser can precisely deliver quantitative energy to a desired region in a non-contact way. Since it can stimulate regions and minutely control parameters such as the intensity, duration and frequency of stimulus, laser is often used for the areas such as low power laser treatment and clinical physiology. This study proposes simulation using pulse diode laser with reliable output and identifies laser parameters that can present a variety of somesthesis. It is found that typically, as frequency and energy increase, the ratio of feeling senses increases, and dominant sense moves from the sense of heat through tactile sense to pain. This study will be baseline data for studies of the sense of heat, tactile sense and pain, contribute to studying neurophysiology sector and be applied to basic clinical research.

Simple LED spectrophotometer for analysis of color information.

A spectrophotometer is the basic measuring equipment essential to most research activity fields requiring samples to be measured, such as physics, biotechnology and food engineering. This paper proposes a system that is able to detect sample concentration and color information by using LED and color sensor. Purity and wavelength information can be detected by CIE diagram, and the concentration can be estimated with purity information. This method is more economical and efficient than existing spectrophotometry, and can also be used by ordinary persons. This contribution is applicable to a number of fields because it can be used as a colorimeter to detect the wavelength and purity of samples.

A new optical technique to monitor joint motion using position sensitive detector.

BACKGROUND: Evaluation of joint movements is essential to choose an appropriate rehabilitation protocol for a patient. OBJECTIVE: The aim of this study is to suggest an alternative optical technique for measurement of joint angle which is convenient, inexpensive, and can be operated in real time. METHODS: According to the principle of the triangulation method, position sensitive detector (PSD) converts reflected light signals into distance-related voltages. Various parameters were investigated to increase detection range and resolution of joint angle measurements. RESULTS: The accuracy of the suggested optical sensor was verified by comparing with a commercial goniometer and 3D motion capture system. CONCLUSIONS: This method can be applied to monitor recovery progress for the patient in rehabilitation and sport science.