Forearm Temperature Research Articles

Physiological effects of exercise in heat while wearing a polyester versus cotton T-shirt in physically active men with obesity: a pilot study.

Obesity may impair evaporation especially during exercising in heat. Polyester sportwear is proposed to improve the evaporation but its effectiveness remains overlooked. We investigated physiological effects of exercise in heat while wearing a polyester versus cotton T-shirt on thermoregulation, perspiration, and cardiovascular regulations. Physically active men with obesity (N.=7; 21.7±1.7 years old; VO<inf>2peak</inf> 36.8±8.7 mL/kg/min; body fat percentage 34.7±4.3%) performed two randomized, crossover walking sessions for 30 mins (27 °C; 12% relative humidity) while wearing a polyester or cotton T-shirt, separated by a 7-day wash out period. Thermoregulation was assessed by measuring tympanic, torso (back and chest), and peripheral (forehead and forearm) skin temperatures. Perspiration rate was estimated as the difference in body weight (pre minus post walking). Heart rate was measured by a Polar heart rate monitor. Systolic and diastolic blood pressure were measured by a sphygmomanometer. All measurements were performed pre, during, and post each session. Two-way ANOVA examined main effects of time, fabric type, and their interactions on the study's outcomes. Back and chest temperatures increased (∆=1.6 °C and 0.9 °C, respectively) while forehead and forearm temperatures decreased (∆=-0.5 °C and -1.6 °C, respectively) over time (P<0.05 for all). Only forehead temperature had an interaction effect for time by fabric type where greater decrease was observed during the polyester T-shirt session compared to the cotton T-shirt session (∆=-0.1 vs. -0.8 °C; P=0.016). Heart rate (∆=27.8 beat/min) and systolic blood pressure (∆=7.5 mmHg) increased while diastolic blood pressure (∆=-5.0 mmHg) decreased over time (P<0.05 for all). No difference observed for perspiratory rate (P>0.05). The current findings do not support the superiority of polyester or cotton sportwear for better thermoregulatory, perspiratory, and cardiovascular regulations in physically active men with obesity. Future research should examine the effectiveness of other alternative fabrics of sportwear for better physiological responses when exercising in the heat, particularly in adults with obesity.

Early and late blood flow changes in the brachial artery following brachial plexus block.

A nerve block causes various hemodynamic changes in the vessel system. The primary objective of the present study is to examine the volume flow values in the brachial artery in the early and late period following an infraclavicular brachial plexus block. The secondary objective is to evaluate arterial diameter, forearm temperature and other Doppler ultrasound measurements in the late period. An infraclavicular brachial plexus block was performed in ASA class I-II patients aged 18-65 years who were to undergo upper extremity surgery. Hemodynamic measurements and the measurement of the Doppler ultrasound parameters at five minutes before and five, 15, 30 minutes, 24, 48 hours after the block. Volume flow was increased at the 30th min after nerve block. A 47.17% decrease in the collected volume flow data was noted between the 30th min and 24th hour, and this change was found to be statistically significant. It is also worth highlighting the decrease in volume flow at 24 hours and 48 hours, which became closer to the volume flow value at time 0, but was still relatively higher than the value at time 0. The increase in volume flow following a change in the flow morphology after an infraclavicular nerve block persists for at least 24 hours. This may be the explanation for clinical advantage in all types of surgery and in particular after fractures, graft and reimplantation surgery.

The effects of local forearm heating and cooling on motor unit properties during submaximal contractions.

What is the central question of this study? How do temperature manipulations affect motor unit (MU) properties during submaximal contractions to the same relative percentage of maximal force? What is the main finding and its importance? MU recruitment patterns are affected by temperature manipulations at the forearm. However, the relationship between MU potential amplitude and recruitment threshold indicates no change to the order or recruitment. Additionally, the MU potential amplitude and firing rate relationship was affected by temperature, suggesting that smaller MUs are more affected by temperature changes than larger MUs. Temperature impacts muscle contractile properties, such that experiments with workloads based on thermoneutral values will produce different relative intensities if maximal force changes due to muscle temperature. We investigated how temperature affected motor unit (MU) properties with contractions performed at the same normalized percentage of maximal force. Twenty participants (10 females) completed evoked, maximal, and trapezoidal voluntary contractions during thermoneutral-, hot-, and cold-temperature conditions. Forearm temperature was established using 25min of neutral (∼32°C), hot (∼44°C) or cold (∼13°C) water circulated through a tube-lined sleeve. Flexor carpi radialis MU properties were assessed with contractions at 30% and 60% MVC relative to each temperature using surface electromyography decomposition. Changes to contractile properties and electromechanical delay from the evoked twitch suggest that muscle contractility was changed from the thermal manipulations (effect size (d)≥0.42, P<0.05). Maximal force was not different between neutral and hot conditions (d=0.16, P>0.05) but decreased in the cold (d≥0.34, P<0.05). For both contraction intensities, MU potential (MUP) amplitude was larger and duration was longer in the cold compared to neutral and hot conditions (d≥1.24, P<0.05). Cumulative probability density for the number of MUs recruited revealed differences in MU recruitment patterns among temperature conditions. The relationship between MU recruitment threshold and firing rate or MUP amplitude was not different among temperature conditions (P>0.05); however, the relationship between MUP amplitude and firing rate was (P<0.05). Local temperature manipulations appear to affect MU recruitment patterns, which may act as compensatory mechanisms to the changes in muscle viscosity and contractile properties due to local temperature changes.

On the use of a novel nanoporous polyethylene (nanoPE) passive cooling material for personal thermal comfort management under uniform indoor environments

Passive cooling materials such as specially designed nanoporous microfibers are nearly transparent to infrared thermal radiation emitted from the human body. Hence, such passive cooling materials have the potential to help indoor occupants attain thermal comfort through regulating the radiative body heat in indoor conditions. In this work, a regular fit women's business shirt made of the nanoporous polyethylene (nanoPE) material was designed and its cooling performance under four uniform indoor conditions was examined. A cotton shirt (CO) with the same size and pattern as the nanoPE shirt was designed and selected as the control. Eighteen female participants underwent eight 80-min trials at four indoor temperatures: 23, 25, 27 and 29 °C. Trials were performed in simulated indoor environments where RH = 60% and the air velocity was kept below 0.10 m/s. Results have demonstrated that participants had significantly lower mean skin temperatures, mean upper torso temperatures and forearm temperatures in nanoPE as compared to CO at 23, 25 and 27 °C. Participants showed the maximum satisfaction with the thermal environment while wearing the CO clothing at 25 °C, whereas they were mostly satisfied with the thermal environment while wearing the nanoPE clothing at 27 °C. Thus, the acceptable air conditioning setpoint temperature could be extended by 1.5 °C from 25.5 to 27 °C while using the nanoPE clothing and thereby, this saves about 9–15% cooling energy. Finally, it was concluded that the nanoPE passive cooling clothing contributes to enhancing indoor thermal comfort under uniform environments and saving significant cooling energy.

Fabrication of Composite Microneedle Array Electrode for Temperature and Bio-Signal Monitoring.

Body temperature and bio-signals are important health indicators that reflect the human health condition. However, monitoring these indexes is inconvenient and time-consuming, requires various instruments, and needs professional skill. In this study, a composite microneedle array electrode (CMAE) was designed and fabricated. It simultaneously detects body temperature and bio-signals. The CMAE consists of a 6 × 6 microneedles array with a height of 500 μm and a base diameter of 200 μm. Multiple insertion experiments indicate that the CMAE possesses excellent mechanical properties. The CMAE can pierce porcine skin 100 times without breaking or bending. A linear calibration relationship between temperature and voltage are experimentally obtained. Armpit temperature (35.8 °C) and forearm temperature (35.3 °C) are detected with the CMAE, and the measurements agree well with the data acquired with a clinical thermometer. Bio-signals including EII, ECG, and EMG are recorded and compared with those obtained by a commercial Ag/AgCl electrode. The CMAE continuously monitors bio-signals and is more convenient to apply because it does not require skin preparation and gel usage. The CMAE exhibits good potential for continuous and repetitive monitoring of body temperature and bio-signals.

Thermographic imaging as alternative method in allergy diagnosis

Allergen sensitization is being diagnosed by commonly available methods in clinical practice—skin prick tests (SPTs) and specific immunoglobulin E test (sIgE). Recently, a new thermographic (TH) method for the assessment of SPT was developed, and it was demonstrated that the TH measurements of forearm temperature distribution during SPT, supported by a mathematical model, offer a new quantification method of allergen-induced skin reactions. The aim of this study is a comprehensive comparison of the TH method with SPT and sIgE techniques. The studies were performed for a group of 51 patients. The SPT and sIgE examinations were done in a routine way. For TH analyses, set of thermograms of both forearms were acquired after prick and analyzed with the use of developed software. All results were converted into categorized scale for comparison. The collected results indicate high correlation coefficients between methods equal to 0.76–0.99. Sensitivity and accuracy of TH assessment in respect of both SPT and sIgE methods is at good level (0.72–0.93). Acceptable level of specificity 0.60–0.88 was also achieved for most allergic responses. Excellent agreement between SPT and sIgE methods was observed which makes the TH assessment competitive. Due to higher precision and sensitivity of digital infrared technology, possibility of making error in diagnosis is significantly reduced. Additional advantage of the TH method relies on an estimation of the skin reactivity which allows highlighting the hypersensitivity patients and automatic correction of the diagnosis.

Investigating the roles of core and local temperature on forearm skin blood flow

We sought to isolate the contributions of core and local temperature on forearm skin blood flow (SkBF), and to examine the interaction between local- and reflexive-mechanisms of SkBF control. Forearm SkBF was assessed using laser-Doppler flowmetry in eight males and eight females during normothermia and hyperthermia (+1.2°C rectal temperature). Mean experimental forearm temperature was manipulated in four, 5min blocks between neutral (A: 33.0°C) and warm (B: 38.5°C) in an A–B–A–B fashion during normothermia, and B–A–B–A during hyperthermia. Mean control forearm skin temperature was maintained at ~33°C. Finally, local heating to 44°C was performed on both forearms to elicit maximal SkBF. Data are presented as a percentage of maximal cutaneous vascular conductance (CVC), calculated as laser-Doppler flux divided by mean arterial pressure. No sex differences were observed in any CVC measures (P>0.05). During normothermia, increasing experimental forearm temperature to 38.5°C elevated CVC by 42±8%max (d=3.1, P<0.001). Subsequently decreasing experimental forearm temperature back down to 33.0°C reduced CVC by 36±7%max (d=2.5, P<0.001). Finally, the second increase in experimental forearm temperature to 38.5°C increased CVC by 25±6%max (d=1.9, P<0.0001). During hyperthermia, decreasing experimental forearm temperature to 33.0°C reduced CVC by 6±1%max (d=0.5, P<0.001). Increasing experimental forearm temperature to 38.5°C increased CVC by 4±2%max (d=0.4, P<0.001). Finally, decreasing experimental forearm temperature to 33.0°C reduced CVC by 8±2%max (d=0.7, P<0.001). Compared to normothermia, CVC responses to local temperature changes during hyperthermia were almost abolished (normothermia: d=1.9–3.1; hyperthermia: d=0.4–0.7). These data indicate that local temperature drives SkBF during normothermia, while reflexive mechanisms regulate SkBF during hyperthermia.

Rapid vs. delayed infrared responses after ischemia reveal recruitment of different vascular beds

Continuous infrared imaging revealed transient changes in forearm temperature during arterial occlusion, reperfusion, and recovery in a healthy subject group. Processing the imaging data with the k-means algorithm further revealed reactive vascular sites in the skin with rapid or delayed temperature amplification. The observed temporal and spatial diversity of blood-flow-derived forearm temperature allow consideration of thermal-imaging guided placement of skin sensors to achieve enhanced sensitivity in monitoring of skin hemodynamics.

Effects of thermoregulatory vasoconstriction on pulse hemoglobin measurements using a co-oximeter in patients undergoing surgery

Study ObjectiveTo validate intraoperative pulse hemoglobin (SpHb) measurements in anesthetized patients with large forearm temperature – fingertip temperature gradients. Designprospective and observational study. SettingOperating room of a university hospital. Patients28 patients undergoing surgery during general anesthesia, requiring arterial blood withdrawal. InterventionsRadial arterial blood pressure, forearm and fingertip skin surface temperatures, and SpHb were monitored. MeasurementsPaired SpHb and arterial hemoglobin (Hb) measurements at different skin-surface temperature gradients. Main ResultsA total of 175 paired SpHb and arterial Hb measurements were analyzed. The mean SpHb to arterial Hb differences in each group were 0.33 ± 1.41g/dL in the < 1°C group of the forearm temperature – fingertip temperature gradient, -0.31 ± 1.24g/dL in the 1 - 2°C group, - 0.59 ± 1.11g/dL in the 2 - 3°C group, and - 0.53 ± 0.87g/dL in the > 3°C group (P < 0.05). The percentage of nonmeasurable SpHb due to low perfusion state was 0% (0 of 115 paired measurements) in the < 1°C group, 6.7% (2 of 30 pairs) in the 1 - 2°C group, 16.7% (3 of 18 pairs) in the 2 - 3°C group, and 66.7% (8 of 12 pairs) in the > 3°C group. ConclusionSpHb measured at fingertip was significantly affected by the perfusion state, with lower perfusion associated with lower SpHb. Thermoregulatory vasoconstriction affects measurement of SpHb.

The Design of Thermal-Insulating Mouse Pad Based on the Effect of Hand Temperature

Carpal Tunnel Syndrome (CTS) is the injury as the result of compression of the median nerve by the swollen muscle and soft tissues at carpal tunnel. This condition is causing pain and making the nerves signal transmissions are slower. The muscle and soft tissues are swollen because of repeated movements and overuse so they dont have enough times for recovery. The muscle and tissues also press the blood flow which supplies oxygen and rich nutrient for them and make them swell. CTS will be worse if the tunnel is smaller because of terrible wrists posture, and if the blood flow is slower which because of cold hand. The symptoms of CTS are pain, tingling, cold, and weak hand. Therapy and surgery can not totally heal this injury so it is much better to prevent it. For reducing the risk of CTS, some actions can be done, for example making the hands always in a normal temperature or warm so the velocity of blood flow will be stable. Today, there is a product called fingerless gloves to keep hands warm but they are not really convenient so in this research another product is designed, which is thermal insulating mouse pad. In this study, an experiment is designed to prove that thermal insulating mouse pad is working effectively. The experiment is done at climatic chamber with 40 students as respondents. There is one single factor of interest which has three levels. The treatments are the condition with no mouse pad, the condition using custom mouse pad, and the condition using thermal insulating mouse pad. Data of experiment is collected by filling the questionnaire and measuring temperature of forearm, wrist, and finger. The experiment result shows that thermal insulating mouse pad can keep hands warm when working with computer.

한지닥 섬유제품의 인체 생리 반응 및 쾌적성 평가

This study performed the evaluation of skin temperature, heart rate, humidity and temperature inside clothing, and subjective sensation to estimate the physiological responses of the human body and its feeling of comfort for developing value-added dox fabric. Experiments were performed on five healthy adult women whose average age was 21, at climate chamber in which temperature, relative humidity and air current were set up below , , 0.2m/s, respectively. Two kinds of clothes were used for the experiments: 100% cotton and dox clothes. The clothes were identical in size and form, and the attire consisted of long-sleeved shirts, long trousers, and socks. The experiment was performed for 30 minutes using ergometer. The results are as follows. 1) It showed low skin temperature of forearm, breast, back, forehead and lower leg in exercise, but high skin temperature of them in recovery. However skin temperature of thigh and foot increased from rest to recovery. 2) It showed significant difference (p

The Thermoregulation Story

Although suppression of thermoregulatory mechanisms by anesthetics is generally assumed, the extent to which thermoregulation is active during general anesthesia is not known. The only thermoregulatory responses available to anesthetized, hypothermic patients are vasoconstriction and nonshivering thermogenesis. To test anesthetic effects on thermoregulation, the authors measured skin-surface temperature gradients (forearm temperature - fingertip temperature) as an index of cutaneous vasoconstriction in unpremedicated patients anesthetized with 1% halothane and paralyzed with vecuronium during elective, donor nephrectomy. Patients were randomly assigned to undergo maximal warming (warm room, humidified respiratory gases, and warm intravenous fluids; n = 5) or standard temperature management (no special warming measures; n = 5). Skin-surface temperature gradients of 4°C or more were prospectively defined as significant vasoconstriction. Normothermic patients (average minimum esophageal temperature = 36.4° ± 0.3°C [SD]) did not demonstrate significant vasoconstriction. However, each hypothermic patient displayed significant vasoconstriction at esophageal temperatures ranging from 34.0 to 34.8°C (average temperature = 34.4° ± 0.2°C). These data indicate that active thermoregulation occurs during halothane anesthesia, but that it does not occur until core temperature is approximately 2.5°C lower than normal. In two additional hypothermic patients, increased skin-temperature gradients correlated with decreased perfusion as measured by a laser Doppler technique. Measuring skin-surface temperature gradients is a simple, noninvasive, and quantitative method of determining the thermoregulatory threshold during anesthesia.

Warming of one hand causes sustained increases in skin surface temperature and water content of the contralateral forearm

Warming of one hand causes sustained increases in skin surface temperature and water content of the contralateral forearm

Temperature Dependency in Motor Skill Learning

ABSTRACT The present study investigated the role of temperature as a contextual condition for motor skill learning. Precision grip task training occurred while forearm cutaneous temperature was either heated (40–45 °C) or cooled (10–15 °C). At test, temperature was either reinstated or changed. Performance was comparable between training conditions while at test, temperature changes decreased accuracy, especially after hot training conditions. After cold training, temperature change deficits were only evident when concurrent force feedback was presented. These findings are the first evidence of localized temperature dependency in motor skill learning in humans. Results are not entirely accounted for by a context-dependent memory explanation and appear to represent an interaction of neuromuscular and sensory processes with the temperature present during training and test.

A Novel Model to Predict Cutaneous Finger Blood Flow via Finger and Rectal Temperatures

To generate a model that predicts fingertip blood flow (BF(f) ) and to cross-validate it in another group of subjects. We used fingertip temperature (T(f)), forearm temperature minus T(f) (T(For-f)), rectal temperature (T(re)), and their changes across time ((lag) T) to estimate BF(f). Ten participants (six male, four female) were randomly divided into "model" and "validation" groups. We employed a passive hot-cold water immersion protocol during which each participant's core temperature increased and decreased by 0.5°C above/below baseline during hot/cold conditions, respectively. A hierarchical multiple linear regression analysis was introduced to generate models using temperature indicators and (lag) T (independent variables) obtained from the model group to predict BF(f) (dependent variable). Mean BF(f) (109.5 ± 158.2 PU) and predicted BF(f) (P-BF(f)) (111.4 ± 136.7 PU) in the model group calculated using the strongest (R(2) = 0.766, p < 0.001) prediction model [P-BF(f) =T(f) × 19.930 + (lag4) T(f) × 74.766 + (lag4) T(re) × 124.255 - 447.474] were similar (p = 0.6) and correlated (r = 0.880, p < 0.001). Autoregressive integrated moving average time-series analyses demonstrated a significant association between P-BF(f) and BF(f) (R(2) = 0.381; Ljung-Box statistic = 8.097; p < 0.001) in the validation group. We provide a model that predicts BF(f) via two practical temperature indicators that can be implemented in both clinical and field settings.

Effect of positive end expiratory pressure on thermo-regulatory function during general anesthesia in patients addicted to smoking

Objective To investigate the effect of positive end expiratory pressure (PEEP) on thermo-regulatory function during general anesthesia in patients addicted to smoking. Methods Twenty adult male ASA Ⅰ or Ⅱ patients who had been smoking more than or equal to 10 cigarettes per day for more than or equal to 6 years were studied. The patients underwent intra-abdominal surgery under general anesthesia and were randomly divided into 2 groups ( n = 10 each): control group (group C) and PEEP group (group P). Anesthesia was induced with propofol, fentanyl and vecuronium and maintained with inhalation of 1%-2% isoflurane and continuous iv infusion of remifentanil and vecuronium. The patients were mechanically ventilated after tracheal intubation. In group P PEEP of 10 cm H2O was added. Temperature probe was inserted into the lower segment of esophagus and placed on the anterior chest wall, medial surface of thigh anterior surface of forearm and palmar surface of the tip of index finger. Mean skin temperature (TMSK) was calculated according to Roberts. MAP, HR, TES, TMSK and the difference between TES and TMSK (TES-MSK) were recorded before induction of anesthesia (T0 ,baseline) and every 30 min after tracheal intubation. Esophageal temperature was taken as threshold of thermo-regulatory peripheral vasoconstriction when the difference between forearm and finger tip temperature = 0 ℃. The gain in the threshold was calculated according to Sessler. Results TES and TES-MSK significantly decreased,while TMsK increased after tracheal intubation in both groups ( P ＜ 0.05). There was no signifieant difference in TES, TMSK, TES-MSK, MAP, HR, the threshold of vasoconstriction and gain between the 2 gronps ( P ＞ 0.05). Conclusion PEEP cannot improve thermo-regulatory function during general anesthesia in smoking-addicted patients. Key words: Respiration, artificial; Body temperature regulation; Smoking; Anesthesia,general

Increased fingertip vascular tone leads to a greater fall in blood pressure after induction of general anesthesia

General anesthesia causes peripheral vasodilation. We thus hypothesized that patients with increased peripheral vascular tone would become more hypotensive after the induction of general anesthesia compared to those without increased peripheral vascular tone. To test this hypothesis, we compared the decrease in blood pressure after anesthetic induction between patients with increased peripheral vascular tone and those without increased peripheral vascular tone. Twentyseven adult patients (10 men and 17 women) who underwent abdominal surgery with general anesthesia were enrolled in this study. In each patient, the peripheral vascular tone was assessed by either the fingertip skin-surface temperature (FSST) or the forearm-fingertip skin-surface temperature gradient (FFSSTG; forearm skin-surface temperature minus FSST). The decrease in blood pressure 15 min after anesthetic induction was larger in patients with an FSST of 29 degrees C or less (FSST = 27.3 +/- 1.6 degrees C; FFSSTG = 5.2 +/- 1.6C) than in those with an FSST of more than 29 degrees C (FSST = 30.8 +/- 1.0 degrees C; FFSSTG = 1.6 +/- 1.2 degrees C). In conclusion, increased fingertip vascular tone (presumably due to thermoregulatory vasoconstriction) before anesthetic induction leads to a greater fall in blood pressure after anesthetic induction.

Effects of a thermal-insulating mouse pad on temperature of forearm and hand during computer tasks

This laboratory experiment studied the effects of a thermal-insulating mouse pad on arm temperature and comfort during computer work. Fourteen subjects performed two 20-min computer tasks (a mouse task and a combined task alternating keyboard and mouse use), under three conditions, namely with: 1) a thermal-insulating pad; 2) a placebo pad; 3) no pad (desktop). The temperatures of the forearm, wrist, hand and fingers were measured with four thermocouples. Comfort and discomfort were determined by two visual analogue scales. No arm temperature differences were found between the experimental conditions after performing the combination task in any location. After the mouse task, however, arm temperature decreased significantly less with the thermal-insulating mouse pad than with the placebo pad. The thermal-insulating pad was rated as more comfortable and less uncomfortable than a regular desktop during mouse tasks. A large size is recommended for the thermal-insulating pad.

Core and skin surface temperature course after normothermic and hypothermic cardiopulmonary bypass and its impact on extubation time

Cardiopulmonary bypass is associated with temperature pertubations that influence extubation time. Common extubation criteria demand a minimum value of core temperature only. The aim of this prospective study was to test the hypothesis that changes in core and skin surface temperature are related to extubation time in patients following normothermic and hypothermic cardiopulmonary bypass. Forty patients undergoing cardiac surgery were studied; 28 patients had normothermic cardiopulmonary bypass (nasopharyngeal temperature >35.5 degrees C) and 12 had hypothermic cardiopulmonary bypass (28-34 degrees C). In the intensive care unit, urinary bladder temperature and skin surface temperature gradient (forearm temperature minus fingertip temperature: >0 degrees C = vasoconstriction, < or =0 degrees C = vasodilatation) were measured at 30-min intervals for 10 h postoperatively. At the same intervals, the patients were evaluated for extubation according to common extubation criteria. On arrival in the intensive care unit the mean urinary bladder temperature was 36.8 +/- 0.5 degrees C in the normothermic group and 36.4+/-0.3 degrees C in the hypothermic group (P = 0.014). The skin surface temperature gradient indicated severe vasoconstriction in the both groups. The shift from vasoconstriction to vasodilatation was faster in normothermic cardiopulmonary bypass patients (138+/-65 min) than in patients after hypothermic cardiopulmonary bypass (186+/-61 min, P = 0.034). There was a linear relation between the time to reach a skin surface temperature gradient = 0 degrees C and extubation time (r2 = 0.56, normothermic group; r2 = 0.82, hypothermic group). The transition from peripheral vasoconstriction to vasodilatation is related to extubation time in patients following cardiac surgery under normothermic as well as hypothermic cardiopulmonary bypass.

Effects of Electrical Stimulation Applied to Paraspinal Tissues on Peripheral Blood Circulation.

To investigate effects of electrical stimulation on the peripheral blood circulation being re­ mote from the stimulated site, human paraspinal tissues were stimulated, and finger skin temperature, acceleration plethymogram (APG) in finger, and finger blood flow (est~mate by vein width) were examined. With some appropriate electrical stimuli (lHz strong, 3Hz strong, 5Hz soft) at the paraspinal tissues of Th cervical vertebral level, skin temperature, the value of APG b/a (blood vessel distensibility) and APG amplitude (magnitude of accel­ eration plethysmogram) in finger significantly rose, and with 3Hz strong stimuli, finger vein width significantly increased, but any effect was not found with 10Hz soft or 30Hz soft stimuli. The thermograph imaging showed that the skin temperature of hand and ulnar forearm rose during the stimuli at Th cervical vertebral level, but not at 3 rd thoracic vertebral level. These findings suggest that through somato-sympathetic reflex, appropriate electri­ cal stimuli to the paraspinal tissues improved peripheral blood circulation of the same der­ matome region being remote from the stimulated site. Besides, even with stimuli conditions that none of the subject experienced any pain or discomfort, electrical stimuli could improve the local peripheral blood circulation being remote from the stimulated site. The similar methods to the electrical stimuli examined in the present study might be useful as a clinical measure, especially at the acute stages of clinical cases in which the direct ap­ proaches to injury site are difficult due to a pain with inflammation or insertion of cast brace.