Relationship between pain and tissue damage due to thermal radiation

1959 ◽  
Vol 14 (3) ◽  
pp. 373-382 ◽  
Author(s):  
Alice M. Stoll ◽  
Leon C. Greene
Keyword(s):  
Thermal Radiation ◽  
Skin Temperature ◽  
Exposure Time ◽  
Tissue Damage ◽  
Pain Threshold ◽  
Human Subjects ◽  
Thermal Inertia ◽  
Pain Sensation ◽  
India Ink

Sites on the volar surfaces of the forearms of human subjects were blackened with India ink and exposed to thermal irradiances of from 50 to 400 mcal/cm2 sec. The exposure time and skin temperature at which threshold pain occurred, and which produced minimal blistering within 24 hours, were noted. The thermal inertia (k⍴c) of the skin was shown to vary directly with the level of irradiance. The receptors effective in mediating the pain sensation were calculated to be at a depth of approximately 200 μ and to have a threshold of approximately 43.2℃. Tissue damage rates with respect to temperature were derived empirically so that damage integrated over the time for which skin temperature was elevated over the pain threshold was equated to unity. The substitution of the ratio of these rates with respect to temperature for the stimulus ratio, in the prediction of the observed discriminable steps in pain sensation intensity, yielded faithful reproduction of the just noticeable differences observed for pain through the range of this sensation. Submitted on September 17, 1958

Adaptation of thermal pain in the skin

1962 ◽  
Vol 17 (4) ◽  
pp. 693-696 ◽  
Author(s):  
Leon C. Greene ◽  
James D. Hardy
Keyword(s):  
Thermal Radiation ◽  
Skin Temperature ◽  
Radiation Intensity ◽  
Pain Threshold ◽  
Human Subjects ◽  
Initial Period ◽  
Pain Thresholds ◽  
Thermal Pain ◽  
Cutaneous Pain ◽  
The Subject

Cutaneous pain thresholds were determined on blackened skin of foreheads and forearms of human subjects over areas of 16 cm2 by recording skin temperature during exposure to thermal radiation for periods up to 50 min. Intensity of stimulus was controlled by the subject so that threshold pain was maintained throughout the exposure. After the initial period of adjustment by the subject, radiation intensity was generally maintained constant although skin temperature for the pain threshold decreased from 44.9 C to 43.8 C. By using an intensity as low as 22 mcal/cm2/sec, threshold pain was evoked in 29 min at a skin temperature of 42.2 C. In both groups, once pain had been established it did not disappear. It is inferred from these observations that thermal pain does not adapt for near-threshold stimulation in the period between onset of pain at 30 sec and termination of stimulation. Submitted on December 26, 1961

Responses of the Rat to Thermal Radiation

1957 ◽  
Vol 189 (1) ◽  
pp. 1-5 ◽  
Author(s):  
J. D. Hardy ◽  
A. M. Stoll ◽  
D. Cunningham ◽  
W. M. Benson ◽  
L. Greene
Keyword(s):  
Thermal Radiation ◽  
Skin Temperature ◽  
Pain Threshold ◽  
Thermal Inertia ◽  
Rat Skin ◽  
Rapid Measurement ◽  
Unanesthetized Animals ◽  
Average Skin ◽  
Skin Temperatures ◽  
Marked Drop

Using the method of rapid measurement of skin temperature during exposure to known amounts of thermal radiation, the ‘thermal inertia’ or kpc product ( k = thermal conductivity, p = density, c = specific heat) was measured for the rat skin. An average kpc value of 84 ± 18 x 10–5 cal2/cm4/sec/°C2 was obtained for the lightly anesthetized animal. This value was independent of the intensity of the radiation, the method of exposing the skin; i.e., shaving, clipping, or depilating, and anesthesia. Administration of 200 mg/kg of azapetine phosphate, a potent adrenolytic agent, was accompanied by a marked drop in skin temperature (4–5°C), but no statistically significant change was observed in the kpc values when compared with the controls. Unanesthetized animals were exposed to high intensity thermal radiation and the animals' reactions observed. Two reactions could be identified, the skin twitch and the escape or withdrawal reactions, occurring at average skin temperatures of 45–46°C and 51–52°C, respectively. A possible correspondence of these reactions to those previously observed to occur in man at these temperatures; i.e., pain threshold and wince threshold, was noted.

An Examination by Forearm EMG on Pain Reaction Time to Radiant Heat

1993 ◽  
Vol 76 (3_suppl) ◽  
pp. 1139-1146 ◽  
Author(s):  
Toshiteru Hatayama ◽  
Kayoko Shimizu
Keyword(s):  
Reaction Time ◽  
Time Delay ◽  
Skin Temperature ◽  
Motor Response ◽  
Pain Threshold ◽  
Radiant Heat ◽  
Repeated Measurements ◽  
Pain Sensation ◽  
Pain Thresholds ◽  
Pain Reaction

The present study was done to estimate rise in skin temperature during a pain reaction time (pain RT) as a means of investigating why a pricking pain threshold, produced by thermal stimulation using time method, often increases during repeated measurements. The pain RT, or the time-delay between occurrence of pain sensation and a subsequent motor response, was measured by making EMG recording on a forearm. The radiant heat stimuli were three, 200, 300, and 350 mcal/sec./cm2, each of which was given through a round radiation window of an algesiometer head. Analysis showed that the pain RTs would be too short to explain higher pain thresholds often found using the time method.

Nociceptive threshold measurements in the cat

1962 ◽  
Vol 17 (6) ◽  
pp. 1009-1012 ◽  
Author(s):  
Charles E. Rice ◽  
D. R. Kenshalo
Keyword(s):  
Thermal Radiation ◽  
Skin Temperature ◽  
Radiation Source ◽  
Human Subjects ◽  
Nociceptive Threshold ◽  
Minimum Duration ◽  
The Mean

Five cats were trained to give a leg-lift response in order to turn off a thermal radiation source. The minimum duration of thermal radiation that would consistently evoke a leg-lift response was taken to be the noxious threshold. The mean calculated skin temperature for the five experimental cats, at threshold, was 52.6 ± 0.35 C. This is compared to a mean calculated skin temperature of 44.5 ± 0.13 C for human subjects under identical conditions of stimulation. Submitted on June 4, 1962

The Influence of Skin Temperature upon the Pain Threshold as Evoked by Thermal Radiation

Science ◽  
1951 ◽  
Vol 114 (2954) ◽  
pp. 149-150 ◽  
Author(s):  
J. D. Hardy ◽  
H. Goodell ◽  
H. G. Wolff
Keyword(s):  
Thermal Radiation ◽  
Skin Temperature ◽  
Pain Threshold

scholarly journals Zastosowanie elektroterapii TENS w łagodzeniu bólu porodowego / Application of TENS electrotherapy in alleviating labour pain

2016 ◽  
Vol 15 (2) ◽  
pp. 59-62
Author(s):  
Magdalena Sowa ◽  
Katarzyna Ciechanowska ◽  
Iwona Głowacka
Keyword(s):  
Electrical Stimulation ◽  
Pain Threshold ◽  
Labour Pain ◽  
Endogenous Opioids ◽  
Transcutaneous Electrical Stimulation ◽  
Pain Sensation ◽  
Transcutaneous Electric Nerve Stimulation ◽  
Obstetric Practice ◽  
Electric Nerve Stimulation ◽  
The Impact

Abstract Introduction. Easing labour pain is an extremely important issue in obstetric practice. Various physiotherapy methods are increasingly often applied in obstetric practice. Transcutaneous electric nerve stimulation (TENS) aiming at central and peripheral modulation of pain sensation is one of them.Aim. The aim of the study was to analyse the impact of transcutaneous electrical stimulation (TENS) on easing labour pain.Summary. The TENS method is regarded as effective since it increases both the pain threshold and secretion of endogenous opioids. Non-pharmacological methods of pain management during labour, including electrotherapy TENS methods are safe and can be used in most patients.

Comparison of responses of warm and nociceptive C-fiber afferents in monkey with human judgments of thermal pain

1978 ◽  
Vol 41 (2) ◽  
pp. 509-528 ◽  
Author(s):  
R. H. LaMotte ◽  
J. N. Campbell
Keyword(s):  
Skin Temperature ◽  
Conduction Velocity ◽  
Mechanical Stimulation ◽  
Human Subjects ◽  
Radiant Heat ◽  
Cumulative Number ◽  
Painful Stimulation ◽  
C Fibers ◽  
Nociceptive Afferents ◽  
Stimulus Temperature

1. Radiant-heat stimuli of different intensities were delivered every 28 s to the thenar eminence of the hand of human subjects and to the receptive fields (RFs) of 58 "mechanothermal nociceptive" and 16 "warm" C-fibers, most of which innervated the glabrous skin of the monkey hand. A CO2 infrared laser under control via a radiometer provided a step increase in skin temperature to a level maintained within +/- 0.1 degrees C over a 7.5-mm-diameter spot. 2. Human subjects categorized the magnitude of warmth and pain sensations evoked by stimuli that ranged in temperature from 40 to 50 degrees C. The scale of subjective thermal intensity constructed from these category estimates showed a monotonically increasing relation between stimulus temperature and the magnitude of warmth and pain sensations. 3. The mechanothermal fibers had a mean RF size of 18.9 +/- 3.2 mm2 (SE), a mean conduction velocity of 0.8 +/- 0.1 m/s, mean thresholds of 43.6 +/- 0.6 degrees C for radiant heat and 5.95 +/- 0.59 bars for mechanical stimulation, and no spontaneous activity. In contrast, warm fibers had punctate RFs, a mean conduction velocity of 1.1 +/- 0.1 m/s, heat thresholds of less than 1 degrees C above skin temperature, no response to mechanical stimulation, and a resting level of activity in warm skin that was suppressed by cooling. 4. The cumulative number of impulses evoked during each stimulation in the nociceptive afferents increased monotonically as a function of stimulus temperature over the range described by humans as increasingly painful (45-50 degrees C). Nociceptive fibers showed little or no response to stimulus temperatures less than 45 degrees C that elicited in humans sensations primarily of warmth but not pain. In contrast, the cumulative impulse count during stimulation of each warm fiber increased monotonically with stimulus temperature over the range of 39-43 degrees C. However, for stimuli of 41-49 degrees C the cumulative impulse count in warm fibers was nonmonotonic with stimulus temperature. Warm-fiber response to stimuli of 45 degrees C or greater usually consisted of a short burst of impulses followed by cessation of activity. 5. The subjective magnitude of warmth and pain sensations in humans and the cumulative impulse count evoked by each stimulus in warm and nociceptive afferents varied inversely with the number, delivery rate, and intensity of preceding stimulations. 6. The results of these experiments suggest the following: a) that activity in the mechanothermal nociceptive C-fibers signals the occurrence of pain evoked by radiant heat, and that the frequency of discharge in these fibers may encode the intensity of painful stimulation; b) that activity in warm fibers may encode the intensity of warmth at lower stimulus temperatures, but is unlikely to provide a peripheral mechanism for encoding the intensity of painful stimulation at higher stimulus temperatures.

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