基于质子共振频率理论的MRI测温方法的准确性研究

对仿组织透明体模进行超声辐照使其发生温度变化，并通过光纤温度传感器和磁共振成像（MRI）测温序列对其进行同步监控研究，以探讨基于质子共振频率（PRF）理论的MRI测温方法的可行性，结果显示该方法能够测量靶区温度变化，但是其测温精度和测温速度均有待进一步提高。     

肝组织超声图像特征参数与温度相关性研究

热疗过程中对组织温度进行实时无创监测是近年来研究的热点和难点.本文对新鲜离体猪肝进行水浴加热实验并采集超声图像;分析了固定感兴趣区域数字减影图像的灰度直方图、灰度共生矩阵和灰度-梯度共生矩阵特征参数与温度的相关性.分析结果表明,其中灰度均值、灰度标准差、灰度熵;4个方向（0°,45°,90°,135°）上的角二阶矩、对比度、逆差矩、相关;灰度分布不均匀性、能量、混合熵、惯性在26～45℃范围内与温度具有较高的相关性.以上11个图像特征可为选择测温模型参数提供参考,并有望应用于组织高温热疗凝固区检测等实际问题.     

光疗对新生儿皮肤体温与核心体温的影响

目的 探讨光疗对皮肤体温（A）与核心体温（R）的影响，以选择能正确地反映体内温度的测温方法。方法 测定了新生儿黄疸60例，在光疗前、光疗下4小时、光疗下8小时及光疗后8小时的A与R。结果 在光疗前无发热，光疗下4小时A与R分别升高0．58℃和0．5℃；A的发热率为46．7％、R的发热率41．7％；光疗下8小时，皮肤体温比光疗4小时升高0．2℃,R仅轻微升高；A的发热率（70．0％），明显高于R的发热率43．3％，也高于光疗下4小时的发热率。在光疗结束后8小时，患儿体温已恢复正常。结论 在光疗下测体温时，应测量核心温度。     

人体组织中血液灌注率和动脉血温度的无损测量研究

由于人体组织中存在血液对流传热和代谢产热，当皮肤表面绝热后，皮肤表面的温度将上升，体表温升值是人体组织中血液灌注率和动脉血温度的函数，根据实际测量的体表温升与时间的关系就可以测出活体组织的血液灌注率和动脉血温度。根据一维Pennes生物传热方程，推导出了体表绝热后人体组织中及皮肤表面温度分布的解析解，并对人体组织中的血液灌注率及动脉血温度进行了实验测量。由于测量过程中利用的只是皮肤表面的温度信息，无须引入外加热源，对人体组织完全不会造成损伤，亦避免了干扰人体组织的正常生理状态，整个测量系统也比较简单。     

电容射频热疗中引入内电极对深部热场分布影响的仿真研究

深部热场控制是电容射频热疗用于深部治癌时尚未能有效解决的难点。本文研究了引人内部电极（接地域接极板）对电容射频（１３．５６ＭＨｚ）热疗深部热场的比吸收率（ＳＡＲ）和程度分布影响。模拟计算表明：引入内电极将显著改变深部热场分布，使８０％以上的ＳＡＲ集中于该电极周围，并使内电极附近成为温度最高的热点；调整内电极位置和加电方式可有效地控制深区ＳＡＲ和温度分布形态，可为深部肿瘤热疗提供新的加热方法。     

组织超声回波时移温度相关性及其无创测温研究

研究生物组织超声回波时移的温度相关性,以期利用这种相关性实现癌热疗中组织温度的无创检测.以去气水和新鲜离体猪肝为实验研究对象,采集其在一定温度范围（20℃～50℃）内的组织背向反射超声回波信号,通过信号分析探寻超声回波时移与温度的相关性,并利用这种相关性进行无创测温.实验结果表明：①组织内超声声速随温度的变化而变化,它与加热区域内的组织热膨胀共同引起了回波时移的变化;②回波时移的变化与温度变化之间有明显的相关性,且具有较为稳定的线性相关函数;③利用组织超声回波时移的温度相关性进行无创测温是可行的.     

水冷式微波偶极子辐射器在生物介质中的温度分布研究

偶极子辐射天线在生物介质中近场辐射及温度特性对腔道微波热疗有重要实用意义。本文在腔内水冷式微波偶极子辐射器近场辐射模型和比吸收率计算了工作基础上，求解相应的生物介质热传导方程，得到了水冷式腔腔道辐射器在生物介质中的温度分布。计算表明，水冷可改善热区温度分布，主要使径向最高温度点由无水冷时贴近辐射器壁向组织深部迁移；径向治疗深度比无水冷时向组织内部延伸；相应的治疗体积则比无水冷时增加。若采取先用小功     

柱面换能器声场在组织中的温度分布估计

本文分析了柱面聚焦换能器的声场特点,剖析了方向比（ratio）与声场的关系。结果表明：声场随方向比的降低而焦点强度减弱,声强最大值前移。在求解声场的基础上,对该类换能器的声场在组织中的温度分布进行估计,给出了组织内温度随时间变化的曲线,分析了方向比（ ratio）对焦区温度分布的影响,为该类换能器的参数选择和组织中的温度分布估计提供了参考。     

空调环境下温度湿度的改变对豚鼠血液流变特性的影响

目的 通过动物实验研究空调环境下温度湿度的改变对机体血液流变特性的影响．为进一步研究空调环境下温度、湿度的改变对机体微循环的影响提供实验依据。方法 采用豚鼠作为实验动物，豚鼠的体质量控制在250—300g之间。实验分为三组，第一组：（31只）豚鼠在温度18℃、湿度70％空调房间内饲养10d；第二组：（31只）豚鼠在温度28℃、湿度70％空调房间内饲养10d；第三组：（31只）豚鼠在温度18℃、湿度50％空调房间内饲养10d。10d后。用心脏穿刺法采集豚鼠血液5ml、肝素抗凝，血液采集完毕后2h内检测血液流变学各项指标。结果 第一组与第二组相比较。各项指标均无显著性差异（P〉0．05），说明空调环境下温度改变对机体血液流变特性无影响。第一组与第三组相比较，全血高切、中切、低切黏度、红细胞比容、红细胞电泳时间均无显著性差异（P〉0．05）。第一组的血浆黏度显著高于第三组（P〈0．01），第一组的全血还原黏度显著低于第三组（P〈0．01）。第一组的红细胞聚集指数、红细胞变形指数低于第三组（P〈0．05）。结论 空调环境下温度的改变对机体血液流变特性的影响不显著；然而湿度改变能引起机体血液流变特性显著改变。因而我们认为空调环境下湿度与机体血液流变特性显著相关。     

利用磁共振成像实现肿瘤热疗中实时无创测温的方法

肿瘤热疗特别是高强度聚焦超声（HIFU）技术，已成为一种重要且非常具有前景的肿瘤治疗方法，温度是直接决定热疗效果的重要参数，实时准确的进行深部无创测温是目前制约肿瘤热疗进一步发展的一项关键技术。近来利用磁共振成像（MRI）进行无创测温，正受到越来越多的研究者的重视。本文简述了MRI无创测温的三种方法，比较了不同测温原理的特点和适用条件，报道了已有研究发展状况，并介绍了尚待解决的问题。     

Contribution of skin thermal sensitivities of large body areas to sweating response

The thermal sensitivity of different parts of the body was investigated by heating large areas of the body surface while the mean skin temperature calculated from Hardy and DuBois ' formula (1938) was always kept constant. The right arm sweating responses recorded under a local thermal clamp were related to changes in segmental skin temperatures of the different parts of the body. The results show that: 1) the various local peripheral signals are projected into integrating structures in the central nervous system; 2) the thermal sensitivity is greater for the head-and-trunk area in comparison with other parts of the body. For resting nude subjects, the formula of Hardy and DuBois remains a pertinent way for evaluating the role of skin thermal signals in the central drive for sweating. The peripheral contribution to the central sweating drive depends only on the skin temperature change and on the size of the stimulated area.     

The influence of model parameter values on the prediction of skin surface temperature: I. Resting and surface insulation

A model is presented of heat transfer and temperature distributions in the skin and superficial tissues. It is based on a finite difference numerical solution of the one-dimensional multilayer coupled bioheat equation. In this paper, the model is used to investigate the influence of the values of parameters chosen to represent the physiological and heat transfer processes on the temperature of the skin under resting conditions and after insulation of the skin surface. Equilibrium resting temperatures were strongly influenced by deep body temperature especially at lower heat transfer coefficients on the skin surface, but slightly affected by the values chosen for skin blood flow and metabolic heat generation; both the heat transfer coefficients and environmental temperature strongly influenced the surface temperature. After surface insulation the temperature elevation was strongly influenced by the thermal conductivities of tissues, skin blood flow and deep boundary temperature; metabolic heat generation was only significantly at unphysiologically high values.     

Metabolic, respiratory and vasomotor responses to heating the scrotum of the ram

1. Oxygen consumption, respiratory frequency, and temperatures of the rectum, common carotid artery, external auditory meatus, and skin on the ears, near the distal end of the metacarpus and metatarsus, upper thigh and mid-side of the body, were measured in five rams before, during and after heating the scrotum. Effects on the woolly animal exposed to ambient temperatures of 17-19 degrees C, and on the shorn animal exposed to ambient temperatures of 5.6-24.5 degrees C, were determined.2. In eight experiments on woolly animals scrotal heating resulted in vigorous panting and a lowering of deep body temperatures by 0.3-1.1 degrees C within 50 min. There was no significant change in oxygen consumption or body skin and upper thigh temperature. Changes in skin temperature of the extremities indicated, on average, a vasodilator response to heating. However, individual responses were unpredictable, there sometimes being dilation and constriction in different extremities of the same animal.3. In twelve experiments on shorn animals in environments below 20 degrees C, oxygen consumption before scrotal heating was higher than when the animal was woolly. Scrotal heating resulted in a fall in oxygen consumption and a lowering of deep body temperatures by 0.2-0.9 degrees C within 50 min. There was no change in respiratory frequency or body skin and upper thigh temperature. As in the woolly animal, vasomotor responses were disorganized, although there was a tendency towards vasodilation.4. In three shorn animals in environments of 20.5 and 24.5 degrees C, oxygen consumption before scrotal heating was only slightly higher than when the animal was woolly. In two of these animals (in 20.5 and 24.5 degrees C) scrotal heating resulted in a slight lowering of oxygen consumption and mild panting, and deep body temperature fell by 0.9 degrees C in 50 min. In the third animal (in 24.5 degrees C) there was no change in oxygen consumption but vigorous panting and vasodilation, and deep body temperature fell by 1.3 degrees C in 50 min.5. In a number of experiments on shorn animals scrotal heating was continued for more than 100 min. Deep body temperature was controlled at a new low level after the initial fall, and the possibility of a resetting of the ;set-point' temperature is discussed.6. The previously unexplained fall in body temperature of the shorn ram in which panting did not follow scrotal heating may now be mainly ascribed to a reduction in metabolic rate. Also, the possible role of cutaneous evaporation should not be discounted. The inhibition of panting in the shorn sheep at environmental temperatures below 20 degrees C remains unexplained.7. Body heating alone, by covering the shorn animal with a sheep skin coat in an environment of 19 degrees C, elicited well organized vasomotor changes in the ears and lower legs.8. As a result of the present study and previous work by others, it is clear that all thermoregulatory mechanisms, with the exception of vasomotor changes, may be influenced in a predictable manner by temperature changes of the scrotum.     

Development of a continuous temperature mapping system using a deep body thermometer

To determine continuous body temperature distribution, an inexpensive temperature mapping system was developed using a deep body thermometer adopting the finite-element method. A stripe with 16 thermocouples was wrapped around the waist of rats to measure body surface temperatures (the boundary conditions). The abdominal deep temperature of the rats was measured from the dorsum using the thermal compensation probe of a deep body thermometer. The abdominal temperature of the rats was mapped by solving a heat conduction equation using surface and deep temperatures obtained in real time. The temperature measured with a thermocouple inserted into the abdominal centre of the rats correlated well with the calculated temperature (r = 0.93, p < 0.01). The system is low cost and simple to use compared with the magnetic resonance temperature mapping system. Our temperature mapping system could potentially result in improved management of patients in critical care medicine.     

A tissue heat transfer model for relating dynamic skin temperature changes to physiological parameters

A physical and mathematical model of the superficial tissues of the body is presented which takes into account tissue physiology, structure and blood supply. The model relates transient temperature changes at the skin surface to underlying physiological parameters. The analysis is based on a one-dimensional finite difference version of the bioheat equation applied to a multi-layered model of the superficial 10 mm of body tissue. Application of the model to the volar forearm predicts that under steady-state conditions skin surface temperature is maintained primarily by heat transfer from tissues below 10 mm, to a lesser extent by perfusion and to a small extent by superficial tissue metabolism. Model predictions of the reheat curve following a 15 s cold challenge to the skin agree closely with preliminary experimental data provided by thermography. The model also provides a physical explanation for the shape of the skin temperature reheat curve. Calculations further suggest that transient skin surface temperature measurements can provide a better indication of dermal perfusion than static temperature measurements as the effects of variations in environmental conditions, deep tissue temperature and tissue metabolism can be reduced.     

Gender differences in thermal comfort and mental performance at different vertical air temperatures

The purpose of this study was to investigate the effects of a thermal environment where air temperature closer to the ground was lower compared to that above on thermal comfort and mental performance in both sexes. Temperatures at the upper and lower parts of the body were controlled independently using a climatic box placed in a climatic chamber. Sixteen healthy subjects (8 males and 8 females) were exposed to the four conditions with various temperature differences between the upper (25°C) and lower part of the body (16, 19, 22, or 25°C). Skin temperature and subjective votes were measured, and two kinds of task using a computer were performed during exposure. Skin temperature on the back for females was higher than that for males during exposure, and the decrease in thigh skin temperature for females under lower air temperature conditions was significantly larger than that for males. A significant difference in thermal comfort at the beginning of the exposure was indicated between genders, especially in the 16 and 19°C conditions, so females became aware of thermal discomfort before males. Although the score of mental performance based on perceptual speed for females was higher than that for males, there was no significant effect from the different vertical air temperatures. The effect of the unequal thermal environment, where air temperature closer to the ground was lower than above, on skin temperature and thermal discomfort for females was significantly higher compared to males.     

The significance of changes in the temperature of the skin and body core of the chicken in the regulation of heat loss

1. The relationship between the temperatures of the hypothalamus, colon and skin and the control of heat loss mechanisms at ambient temperatures from 20 to 40 degrees C has been studied in unanaesthetized chickens.2. The temperatures of the core and feathered skin varied by not more than 5 degrees C throughout the full range of ambient temperature but the comb, shank and toe varied by up to 20 degrees C and exhibited wide fluctuations in constant environmental conditions.3. At an ambient temperature of 26-27 degrees C, the fluctuations ceased at all of the naked skin sites and there was evidence of a concurrent decrease in the tissue insulation of the extremities. No such change could be detected in the feathered skin.4. Analysis of the various body temperatures suggested that the onset of thermal panting was consistently related to the increment in hypothalamic temperature and that this relationship was influenced both by the peripheral and extra-cranial deep body temperatures.     

Analysis of sensible heat exchanges from a thermal manikin

The present work is dedicated to the analysis of dry heat exchanges as measured by a thermal manikin placed in still air. We believe that the understanding of some fundamental aspects governing fluid flow and heat transfer around three-dimensional bodies such as human beings deserves appropriate attention. This should be of great significance for improving physiological models concerned with thermal exposures. The potential interest of such work can be directed towards quite distinct targets such as working conditions, sports, the military, or healthcare personnel and patients. In the present study, we made use of a climate chamber and an articulated thermal manikin of the Pernille type, with 16 body parts. The most common occidental postures (standing, sitting and lying) were studied. In order to separate heat losses due to radiation and convection, the radiative heat losses of the manikin were significantly reduced by means of a shiny aluminium coating, which was carefully applied to the artificial skin. The air temperature within the test chamber was varied between 13°C and 29°C. The corresponding mean differences between the skin and the operative temperatures changed from 3.8°C up to 15.8°C. The whole-body heat transfer coefficients by radiation and convection for both standing and sitting postures are in good agreement with those in the published literature. The lying posture appears to be more efficient for losing heat by convection. This is confirmed when the heat losses of each individual part are considered. The proposed correlations for the whole body suggest that natural convection is mainly laminar.     

运动过程中人体工作肌体表皮肤及鼓膜温度的变化

背景：运动过程中体温的变化可为推算人体能量代谢提供新的方法和思路。 目的：通过对人体有氧运动过程中体表温度和核温变化的即时检测,来探讨一种能量代谢测试方法的新思路,以适应现代竞技体育运动对体能即时检测的要求。 方法：对未经训练的18~23周岁在校生共34名(男女各17名)进行研究,在有氧运动的条件下,分别即时测试运动过程中体核温度、体表温度和鼓膜温度的变化。 结果与结论：结果表明,运动过程中人体核温度、鼓膜温度变化不显著,而工作肌的体表皮肤温度在运动0~2 min下降,  2~4 min变化平缓,4~6 min上升,第6分钟时出现峰值,6~8 min再次下降,8~10 min趋于平缓,10 min至结束再次上升。而且所有工作肌的体表皮肤温度几乎都在运动的第6分钟到达最高值。说明运动过程中工作肌的表面温度有明显的规律性变化。     

Electro-mechanical stability of surface EMG sensors

This study compared the performance of surface electromyographic (sEMG) sensors for different detection conditions affecting the electro-mechanical stability between the sensor and its contact with the skin. These comparisons were made to gain a better understanding of how specific characteristics of sensor design and use may alter the ability of sEMG sensors to detect signals with high fidelity under conditions of vigorous activity. The first part of the study investigated the effect of different detection surface contours and adhesive tapes on the ability of the sensor to remain in electrical contact with the skin. The second part of the study investigated the effects of different skin preparations and hydrophilic gels on the production of movement artifact resulting from sinusoidal and impact mechanical perturbations. Both parts of the study evaluated sensor performance under dry skin and wet skin (from perspiration) conditions. We found that contouring the detection surface and adding a more adhesive double-sided tape were effective in increasing the forces needed to disrupt the electrical contact between the electrodes and the skin for both dry skin and wet skin conditions. The mechanical perturbation tests demonstrated that hydrophilic gel applied to the detection surface of the sensor produced greater movement artifacts compared to sensors without gel, particularly when the sensors were tested under conditions in which perspiration was present on the skin. The use of a surfactant skin preparation did not influence the amount of movement artifacts that resulted from either the sinusoidal or impact perturbations. The importance of these findings is discussed in terms of their implications for improving sEMG signal fidelity through sensor design modifications and procedures for interfacing them with the skin.