Relationship between pulse rate and pulse width for a constant-intensity level of electrocutaneous stimulation

1985 ◽  
Vol 13 (5) ◽  
pp. 373-383 ◽  
Author(s):  
Andrew Y. J. Szeto
Keyword(s):  
Pulse Rate ◽  
Pulse Width ◽  
Electrocutaneous Stimulation ◽  
Intensity Level ◽  
Constant Intensity

Electrocutaneous Pulse Rate and Pulse Width Psychometric Functions for Sensory Communications

1979 ◽  
Vol 21 (2) ◽  
pp. 241-249 ◽  
Author(s):  
Andrew Y. J. Szeto ◽  
John Lyman ◽  
Ronald E. Prior
Keyword(s):  
Pulse Rate ◽  
Pulse Width ◽  
Communication Systems ◽  
Transfer Functions ◽  
Frequency Discrimination ◽  
Just Noticeable Difference ◽  
Electrocutaneous Stimulation ◽  
Maximum Frequency ◽  
Sensory Communication

Psychometric functions of pulse rate (PR) and pulse width (PW) from electrocutaneous stimuli were determined using the method of comparative judgments. The study revealed that changes in PR were more easily detected than changes in PW, as measured by the percent of just noticeable difference (jnd). The PR jnd data from test subjects indicated that maximum frequency discrimination occurred near 20 pulses per second. Using the PR and PW psychometric curves, compensatory transfer functions can be determined which will improve the efficacy of sensory communication systems based on electrocutaneous stimulation.

Electrocutaneous Coding of Information

1977 ◽  
Vol 21 (4) ◽  
pp. 331-334
Author(s):  
Lura I. Raple ◽  
John Lyman
Keyword(s):  
Phase Shift ◽  
Factorial Design ◽  
Analysis Of Variance ◽  
Pulse Width ◽  
Discrimination Threshold ◽  
Electrocutaneous Stimulation ◽  
Threshold Distance ◽  
Electrical Stimuli ◽  
Frequency Pulse

Responses to electrocutaneous stimulation were investigated using the two point discrimination threshold as a means of providing information about the range of sensitivity to electrical stimuli. A complete factorial design was used to investigate the effects of frequency, pulse width, and phase shift on the threshold distance at which two electrocutaneous stimuli can be discriminated. Results were analyzed by an analysis of variance. The two point discrimination threshold was found to be significant for frequency, pulse width, and the interaction between pulse width and phase shift. Electrocutaneous sensitivity was determined by the level at which the minimum two point discrimination threshold occurred.

Effects of Pulse Width, Pulse Rate and Paired Electrode Stimulation on Psychophysical Measures of Dynamic Range and Speech Recognition in Cochlear Implants

2012 ◽  
Vol 33 (4) ◽  
pp. 489-496 ◽  
Author(s):  
Raymond M. Bonnet ◽  
Peter-Paul B. M. Boermans ◽  
Otto F. Avenarius ◽  
Jeroen J. Briaire ◽  
Johan H. M. Frijns
Keyword(s):  
Speech Recognition ◽  
Cochlear Implants ◽  
Pulse Rate ◽  
Pulse Width ◽  
Dynamic Range ◽  
Electrode Stimulation

scholarly journals Diminution and enlargement of the mosquito rhabdom in light and darkness.

1975 ◽  
Vol 65 (5) ◽  
pp. 583-598 ◽  
Author(s):  
R H White ◽  
E Lord
Keyword(s):  
Light Intensity ◽  
Aedes Aegypti ◽  
Dark Adaptation ◽  
Light Adaptation ◽  
Constant Volume ◽  
Intensity Level ◽  
Constant Intensity ◽  
Rates Of Change

The rhabdoms of the larval ocelli of the mosquito Aedes aegypti undergo morphological light and dark adaptation over periods of hours. The rhabdom enlarges during dark adaptation and grows smaller during light adaptation. Diminution is exponential, enlargement linear, and rates of change are proportional to log light intensity. Rhabdoms maintained at a constant intensity level off at a constant volume proportional to log intensity. We argue that changes in rhabdom volume after changes in light intensity reflect an influence of light on the turnover of photoreceptro membrane, and that the volumes at which rhabdoms level off represent equilibria between opposed processes of membrane loss and renewal.

Psychophysical and Speech Studies with an Electrotactile Speech Processor

1987 ◽  
Vol 96 (1_suppl) ◽  
pp. 87-89 ◽  
Author(s):  
P. J. Blamey
Keyword(s):  
Cochlear Implant ◽  
Pulse Rate ◽  
Pulse Width ◽  
Speech Comprehension ◽  
Electrode Position ◽  
Speech Discrimination ◽  
Formant Frequency ◽  
Speech Processor ◽  
Multiple Channel ◽  
Second Formant

A multiple-channel electrotactile speech processor worn on the fingers of one hand has been constructed. This processor implements a speech-coding strategy that presents the second formant frequency by electrode position, fundamental frequency by electrical pulse rate, and amplitude envelope by pulse width. This strategy is similar to the one used by the Nucleus cochlear implant. Psychophysical tests with normally hearing and profoundly deaf subjects have measured the discrimination of stimuli differing in pulse rate, electrode, or pulse width. The levels of performance were comparable to those for cochlear implant patients except for pulse rate discrimination. Three untrained normally hearing adults using electrotactile stimulation without hearing or lipreading scored significantly better than chance for a range of two alternative forced-choice speech discrimination tasks. Provided that subjects can learn to associate linguistically meaningful concepts with tactile sensations, an improved level of speech comprehension may be achieved when the electrotactile speech processor is used together with lipreading.

Are HOLZ lines kinematic in off-zone-axis orientation?

1993 ◽  
Vol 51 ◽  
pp. 692-693
Author(s):  
J. M. Zuo ◽  
A. L. Weickenmeier ◽  
R. Holmestad ◽  
J. C. H. Spence
Keyword(s):  
Structure Determination ◽  
Standard Procedure ◽  
High Order ◽  
Zone Axis ◽  
Great Promise ◽  
Line Position ◽  
Measured Intensity ◽  
Constant Intensity ◽  
Axis Orientation ◽  
Diffraction Condition

The application of high order reflections in a weak diffraction condition off the zone axis center, including those in high order laue zones (HOLZ), holds great promise for structure determination using convergent beam electron diffraction (CBED). It is believed that in this case the intensities of high order reflections are kinematic or two-beam like. Hence, the measured intensity can be related to the structure factor amplitude. Then the standard procedure of structure determination in crystallography may be used for solving unknown structures. The dynamic effect on HOLZ line position and intensity in a strongly diffracting zone axis is well known. In a weak diffraction condition, the HOLZ line position may be approximated by the kinematic position, however, it is not clear whether this is also true for HOLZ intensities. The HOLZ lines, as they appear in CBED patterns, do show strong intensity variations along the line especially near the crossing of two lines, rather than constant intensity along the Bragg condition as predicted by kinematic or two beam theory.

No effect of artificial gravity on lung function with exercise training during head-down bed rest

2015 ◽  
pp. 1-7
Author(s):  
Longxiang Su ◽  
Yinghua Guo ◽  
Yajuan Wang ◽  
Delong Wang ◽  
Changting Liu
Keyword(s):  
Lung Function ◽  
Pulse Rate ◽  
Vital Capacity ◽  
Pulmonary Ventilation ◽  
Bed Rest ◽  
Forced Expiratory Volume ◽  
Observation Time ◽  
Artificial Gravity ◽  
Postural Changes ◽  
Expiratory Flow

AbstractTo explore the effectiveness of microgravity simulated by head-down bed rest (HDBR) and artificial gravity (AG) with exercise on lung function. Twenty-four volunteers were randomly divided into control and exercise countermeasure (CM) groups for 96 h of 6° HDBR. Comparisons of pulse rate, pulse oxygen saturation (SpO2) and lung function were made between these two groups at 0, 24, 48, 72, 96 h. Compared with the sitting position, inspiratory capacity and respiratory reserve volume were significantly higher than before HDBR (0° position) (P< 0.05). Vital capacity, expiratory reserve volume, forced vital capacity, forced expiratory volume in 1 s, forced inspiratory vital capacity, forced inspiratory volume in 1 s, forced expiratory flow at 25, 50 and 75%, maximal mid-expiratory flow and peak expiratory flow were all significantly lower than those before HDBR (P< 0.05). Neither control nor CM groups showed significant differences in the pulse rate, SpO2, pulmonary volume and pulmonary ventilation function over the HDBR observation time. Postural changes can lead to variation in lung volume and ventilation function, but a HDBR model induced no changes in pulmonary function and therefore should not be used to study AG CMs.

Modified Earpieces and CROS for High Frequency Hearing Losses

1968 ◽  
Vol 11 (1) ◽  
pp. 204-218 ◽  
Author(s):  
Elizabeth Dodds ◽  
Earl Harford
Keyword(s):  
Hearing Loss ◽  
Hearing Aids ◽  
High Frequency ◽  
Hearing Aid ◽  
Sound Field ◽  
Intensity Level ◽  
Test Results ◽  
High Frequency Hearing Loss ◽  
Increased Sensitivity ◽  
Difficult Cases

Persons with a high frequency hearing loss are difficult cases for whom to find suitable amplification. We have experienced some success with this problem in our Hearing Clinics using a specially designed earmold with a hearing aid. Thirty-five cases with high frequency hearing losses were selected from our clinical files for analysis of test results using standard, vented, and open earpieces. A statistical analysis of test results revealed that PB scores in sound field, using an average conversational intensity level (70 dB SPL), were enhanced when utilizing any one of the three earmolds. This result was due undoubtedly to increased sensitivity provided by the hearing aid. Only the open earmold used with a CROS hearing aid resulted in a significant improvement in discrimination when compared with the group’s unaided PB score under earphones or when comparing inter-earmold scores. These findings suggest that the inclusion of the open earmold with a CROS aid in the audiologist’s armamentarium should increase his flexibility in selecting hearing aids for persons with a high frequency hearing loss.

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