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At least 649 records · Page 36Linked to original sources
PubMed1989

Controlled comparison of ketanserin and nifedipine in Raynaud's phenomenon.

Twenty-eight patients suffering from either primary or secondary Raynaud's phenomenon were treated with nifedipine and ketanserin. Each patient was treated with one of the two drugs administered after an adequate washout period. Furthermore each patient was submitted before and after treatment with each drug to computerized digital thermometry to evaluate the therapeutic response. The data obtained during the intake of the two drugs at zero, five, and twenty-three minutes were compared with thermometry-relevant baseline data at the same periods. Ketanserin proved to be useful in the treatment of Raynaud's phenomenon and statistically significantly superior (alpha less than 0.05) with respect to nifedipine in the thermometric controls and also in the subjective evaluation of the patients (p less than 0.02). In this study nifedipine did not show particular efficacy. Furthermore only 2 patients had to discontinue treatment with ketanserin, whereas 8 had to discontinue treatment with nifedipine (p less than 0.001).

Adult↗
PubMed1991

Efficacy of ketanserin in the therapy of Raynaud's phenomenon: thermometric data.

After a two-week washout (WO) period with placebo 1 capsule/bid, 12 patients suffering from stable Raynaud's phenomenon were treated with ketanserin (K) 40 mg/bid for fifteen days. Blood pressure, heart rate, and laboratory parameters were evaluated at the end of each period. Patients used diary cards to record the number, duration, and intensity of attacks. Computerized thermometry of the fingers was evaluated at basal temperature after acclimatization, 23 degrees C for thirty minutes; after cold test, 10 degrees C for five minutes; and after thermal recovery, 23 degrees C for eighteen minutes. Results were analyzed statistically by use of Student's t-test for paired data (p less than 0.05). No marked changes were observed in the symptoms of the attacks, but K proved effective in significantly reducing the number and duration of daily attacks and in promoting their spontaneous regression. Thermometry revealed a parallel increase in temperatures, particularly basal and recovery values. The data suggest increased flow and decreased vasospasm following 5-HT2 receptor blockade.

Adult↗
PubMed1991

Behavioral aspects of temperature-taking.

Ear thermometry addresses two basic psychological aspects of fevers. The first one is obvious: the battle of the rectal temperature can be eliminated by ear thermometry. The second one addresses the overtreatment of tactile fevers. Tactile temperature taken by feeling the forehead occurs in 50% to 90% of homes. Half of warm foreheads occur in afebrile children who are warm because they're releasing heat generated by a recent activity or bath. If an actual temperature were measured, these children wouldn't be mislabeled as having fever and unnecessarily treated.

Age Factors↗
PubMed2004

Accuracy of MR temperature measurement based on chemical shift change for radiofrequency ablation using hook-shaped electrodes.

The purpose of the current study is to evaluate the accuracy of MR thermometry for radiofrequency ablation (RFA) with hook-shaped electrodes. The objects were eight extracted bovine livers. The chemical shift change was calculated from MR images acquired with a spoiled gradient echo sequence and compared with the temperature directly measured with a thermocouple. Linear regression was established between them with a coefficient of -0.0110+/-0.0007 ppm/ degrees C and errors were calculated as -0.50+/-7.50 degrees C. MR thermometry is capable of monitoring temperature for RFA.

Animals↗
PubMedDate not supplied

Site and disease selection for hyperthermia clinical trials.

Significant progress has been made in the past 20 years in understanding the biological basis of hyperthermia-induced cytotoxicity, thermoenhancement of radiation therapy and chemotherapy, and in the development of clinically applicable microwave, radiofrequency, ultrasound and thermometry equipment. Numerous uncontrolled trials have suggested strongly that hyperthermia in conjunction with radiation therapy or chemotherapy may contribute to improved local control rates for recurrent or metastatic cancer without excessive morbidity. Carefully designed and well-controlled site and disease-specific prospective randomized trials with standardized hyperthermia and radiation therapy techniques, adequate thermometry, precise end points for tumour control and normal tissue toxicity are now essential to establish the role of hyperthermia in cancer management. Criteria for tumour site selection will be explored for trials employing radiation therapy and local-regional hyperthermia. Examples of sites selected will be presented which represent areas that can, with current technology, usually be adequately heated, and in which significant patient benefit may result from improved local-regional control.

Clinical Trials as Topic↗
PubMedDate not supplied

The application of thermal dose in clinical trials.

When large human tumours are heated, spatial temperature (T) variation is high and poorly predictable with current hyperthermia technology. Invasive thermometry is thus necessary to document efficacy, and thermal mapping or multisensor thermometry can increase the yield of information without increasing the extent of invasiveness. The amount of temperature, time and spatial (T, t, x) data generated in a typical treatment is overwhelming, but can be made comprehensible by the application of thermal dose (TD) analysis. The isoeffective basis of the analysis reviewed here is likely to be modified as more biophysical information becomes available but, at present, serves the purpose of data condensation and treatment comparison. Real-time TD analysis may help to assure treatment reproducibility and may assist in discerning thermal dose-response relationships in prospective clinical trials.

Animals↗
PubMedDate not supplied

Modified thermal clearance technique for determination of blood flow during local hyperthermia.

The thermal clearance method utilizes the rate of temperature decay after the applied power is turned off to estimate the local blood flow. A limitation of this method has been its inability to account for the contribution of thermal conduction to the rate of temperature decay. As a result, the blood flow is generally overestimated. A modification of the thermal clearance method is described in this paper which enables the conduction component to be determined. Profiles of the tissue temperature are obtained in three mutually orthogonal directions about the point where thermal clearance is measured. The Laplacian of the temperature is evaluated from these profiles by the method of finite differences. The tissue thermal conductivity is estimated from literature values. The greatest source of error is the uncertainty in the location of the washout point in each catheter. Strict thermometry requirements must be adopted to reduce the localization error to +/- 0.25 cm. The thermometry catheters should be orthogonal to within +/- 10 degrees and all three catheters should be in contact at the washout point. The methodology was tested in a phantom, studied by use of a computer model, and implemented in the clinic. The experimental error in the conduction component is typically 50%. The resulting error in the blood flow depends on the relative rates of energy removal by blood flow and thermal conduction. When perfusion is the dominant mode of energy removal, the resulting uncertainty in the blood flow is typically in the range 20-30%.

Blood Flow Velocity↗
PubMedDate not supplied

Temperature dependence of canine brain tissue diffusion coefficient measured in vivo with magnetic resonance echo-planar imaging.

The intensity of conventional spin-echo diffusion-weighted magnetic resonance (MR) images is approximately linearly dependent on temperature over a restricted range using conventional diffusion-weighted spin-echo magnetic resonance imaging (MRI). However, conventional diffusion-weighted MRI is too motion sensitive for in vivo thermometry. The present work evaluated rapid diffusion-weighted echo-planar imaging (EPI), which is less sensitive to motion, for application to non-invasive thermometry in acrylamide gel materials and in vivo in canine brain tissue for applications in therapeutic hyperthermia. The rapidly switched, strong gradients needed for EPI were achieved using a 'local' z-axis gradient coil. Gel materials were heated with a small (10 cm diameter) spiral surface microwave (MW) applicator at 433 MHz, while in vivo heating was accomplished with whole body RF hyperthermia using an annular phased array (130 MHz). The MW or RF fields associated with heating and imaging (64 MHz) were decoupled using bandpass filters providing isolation in excess of 100 dB. This isolation was sufficient to allow simultaneous imaging and MW or RF heating without deterioration of the image signal-to-noise ratio. Using this system in a gel, temperature sensitivity of the diffusion coefficient was observed to be (3.04 +/- 0.03)%/degrees C which allowed temperature changes of 0.55 degrees C to be resolved for a 1.8 cm3 region in < 10 s of data acquisition. In vivo, cardiac gating of the pulse sequence was necessary to minimize motion artifacts in the brain. The temperature sensitivity of brain tissue was (1.9 +/- 0.1)%/degrees C allowing temperature changes of 0.9 degrees C to be resolved in a 0.9 cm3 volume in < 10 s of data acquisition. We conclude that with further optimization of the data acquisition conditions it will be possible to determine 0.5 degrees C temperature changes in 1 cm3 volumes in < 10 s using this technique.

Animals↗
PubMedDate not supplied

The feasibility of MRI feedback control for intracavitary phased array hyperthermia treatments.

Temperature feedback control has the potential to enhance hyperthermia treatments by providing more uniform heating of the target volume and improving the transient temperature response. A multivariable least squares batch algorithm was used to estimate system parameters for simulated prostate hyperthermia treatments. A multi-input, multi-output (MIMO) linear quadratic regulator (LQR) controller was designed for prostate hyperthermia treatments with an intracavitary phased array. A parametric study was performed for the one-dimensional control case, investigating factors relevant to magnetic resonance imaging (MRI) feedback control such as spatial resolution of temperature measurements (size of the averaging volume), sampling rate (image acquisition time), thermometry noise, control width, control depth, physiological parameter changes and reference input structure. Simulations utilizing the two dimensional (2-D) thermometry of MRI and the 2-D focusing capabilities of phased arrays demonstrated that near field heating can be controlled such that the size and shape of the heated volume can be tailored in 2-D. The control algorithms developed in this study show promising potential for incorporation into a non-invasive prostate hyperthermia system utilizing MRI feedback.

Acoustics↗
PubMed1993

Differences between arterial and venous occlusion in microvascular surgery.

Between November 1985 and November 1988 11 patients developed arterial occlusion after microvascular anastomoses, 10 patients venous occlusions and five combined arterial and venous occlusions. We undertook a retrospective study to see whether colour, capillary refill, thermometry, or laser Doppler measurements could distinguish arterial and venous occlusions. Neither skin thermometry nor total backscattered light intensity change and flow band width (laser Doppler measurements) were significantly different (p > 0.05) between arterial and venous occlusions, but there were significant differences in colour (p = 0.006), capillary refill (p = 0.007), and laser Doppler flow (p = 0.02). The values obtained from cases with combined arterial and venous occlusions were like those of a venous occlusion or of an arterial occlusion or somewhere in between. Although none of the variables was diagnostic, we advise that the suspect vascular anastomosis should first be checked during reoperation. If an occluded anastomosis is found, one should also check the other anastomosis because occlusion of both artery and vein cannot be reliably detected.

Anastomosis, Surgical↗
PubMed1994

Combined treatment of radiotherapy and hyperthermia for unresectable hepatocellular carcinoma.

Eighty-four patients with unresectable primary hepatocellular carcinoma due either to locally advanced lesion or to association with liver cirrhosis were treated with combined radiotherapy and hyperthermia from April 1988 to January 1991. Purpose of this study was to assess thermometry, response rate, toxicity, and survival in those patients. External radiotherapy was given with a total of 30.6 Gy/3.5 wks. Hyperthermia was given twice a week with a total of 6 treatment sessions using an 8 MHz radiofrequency capacitive type heating machine. Each hyperthermia session was started within 30 min following radiotherapy and continued for 30-60 min. Thermal data were analysed with maximum, minimum, and average temperatures of the tumors. Thermal mapping was also done. In thermometry results, maximum, minimum, and average temperatures of the tumors were 41.9 +/- 1.3 degrees C, 39.9 +/- 1.0 degrees C, and 40.8 +/- 0.9 degrees C, respectively. The fraction over 40 degrees C was 73 +/- 32% with a wide variation from 15% to 100%. Among 67 assessable patients, 27 patients showed tumor regression of more than 50% of the original tumor volume (40.3% response rate). Symptomatic improvement was observed in 78.6% of the patients. Acute toxicities during the treatment were mostly acceptable local pain (51.2%) and local fat necrosis (13.1%). The actuarial 1-year, 2-year, and 3-year survival rates were 44.8%, 19.7%, and 15.6%, respectively. Median survival was 6 months. In view of acceptable toxicities and the current rate of survival, further evaluation of combined treatment of radiotherapy and hyperthermia for unresectable hepatocellular carcinoma is warranted.

Carcinoma, Hepatocellular↗
PubMed2003

Infrared imaging technology and biological applications.

Temperature is the most frequently measured physical quantity, second only to time. Infrared (IR) technology has been utilized successfully in astronomy (for a summary,see Hermans-Killam, 2002b) and in industrial and research settings (Gruner, 2002; Madding, 1982, 1989; Wolfe & Zissis, 1993) for decades. However, fairly recent innovations have reduced costs, increased reliability, and resulted in noncontact IR sensors offering mobile, smaller units of measurement (EOI, 2002; Flir, 2000, 2001,2002). The advantages of using IR imaging are (1) rapidity in the millisecond range, facilitating measurement of moving targets, (2) noncontact procedures, allowing measurements of hazardous or physically inaccessible objects, (3) no interference and no energy lost from the target, (4) no risk of contamination, and (5) no mechanical effect on the surface of the object. All these factors have led to IR technology's becoming an area of interest for new kinds of applications and users. In both manufacturing and quality control, temperature plays an important role as an indicator of the condition of a product or a piece of machinery (EOI, 2002; Flir, 2000, 2001, 2002; Raytek, 2002). In medical and veterinary applications, IR thermometry is increasingly used in organ diagnostics, in the evaluation of sports injuries and the progression of therapy, in disease evaluation (e.g, breast cancer, arthritis, and SARS; Flir, 2003), and in injury and inflammation examinations in horses, livestock (Tivey & Banhazi, 2002), and zoo animals (Hermans-Killam, 2002a; Thiesbrummel, 2002). Lastly, physiological expressions of life processes in animals (Kastberger, Winder, & Steindl, 2001; Stabentheiner, Kovac, & Hagmüller, 1995; Stabentheiner, Kovac, & Schmaranzer, 2002; Stabentheiner & Schmarnzer, 1987) and plants (Bermadinger-Stabentheiner & Stabentheiner, 1995) can be monitored. The most recent field in which IR technology has been applied is animal behavior. This article focuses on the practical options for noncontact IR thermometry--in particular, in biological applications.

Animals↗
PubMed2003

Temperature taking: children's preferences.

Children aged between six and 15 years on two paediatric wards of one NHS trust were invited to take part in a study to find out whether they preferred digital underarm thermometry or tympanic thermometry. The study was conducted as part of the Nursing and Midwifery Research and Practice Development Project for the Southern Derbyshire Acute Hospitals NHS Trust. In the six to ten year age group (n = 39), 74 per cent of the children preferred the tympanic thermometer, as did 91 per cent in the 11-15 year age group (n = 44). Children/young people in both age groups commented that the tympanic thermometer was quicker and more comfortable. All children over two years now have their temperature taken using the tympanic thermometer, with the exception of those for whom it would not be medically appropriate or who express dislike for this method.

Adolescent↗
PubMed1999

[Active radiation telethermometry in the complex diagnosis of ovarian tumors].

An active remote radiation thermometry was used in the diagnosis and differential diagnosis of ovarian tumours by determining the heat flow from the area of projection of the ovaries and control background. Overall fourty three patients with ovarian tumours were examined by this method. Significance of the results secured was verified during the histological technique-aided operation. The authors have come to the conclusion that remote thermometry involving loading tests is a simple supplementary method of investigation that is helpful in diagnosing of both benign and malignant ovarian tumours.

Adult↗
PubMed2003

[Early diagnosis and prognosis of severity in frostbite of the extremities].

Early diagnosis of the depth of extremity frostbite is of little effect without additional means of examination (from 39.9% to 43.6% of correct findings at the pre- and intrahospital stages of medical care). It can be improved (up to 61.5% of verified answers) when using the method of calculation of cold loading. The combination of distant infrared thermography (DIRT) and contact thermometry allows to make the verification as great as 78.3%. If the task of the diagnosis is only to determine the form of frostbite (superficial or profound), using the temperature criteria (by the data of contact thermometry) and thermographic algorithms (on the basis of the data of DIRT) is shown to improve diagnosis up to 88.4%-92.4% of correct answers on the hands and up to 82.5%-86.8% on the feet.

Frostbite↗
PubMedDate not supplied

A critical appraisal of 98.6 degrees F, the upper limit of the normal body temperature, and other legacies of Carl Reinhold August Wunderlich.

OBJECTIVE: To evaluate critically Carl Wunderlich's axioms on clinical thermometry. DESIGN: Descriptive analysis of baseline oral temperature data from volunteers participating in Shigella vaccine trials conducted at the University of Maryland Center for Vaccine Development, Baltimore. SETTING: Inpatient clinical research unit. PARTICIPANTS: One hundred forty-eight healthy men and women aged 18 through 40 years. MAIN MEASUREMENTS: Oral temperatures were measured one to four times daily for 3 consecutive days using an electronic digital thermometer. RESULTS: Our findings conflicted with Wunderlich's in that 36.8 degrees C (98.2 degrees F) rather than 37.0 degrees C (98.6 degrees F) was the mean oral temperature of our subjects; 37.7 degrees C (99.9 degrees F) rather than 38.0 degrees C (100.4 degrees F) was the upper limit of the normal temperature range; maximum temperatures, like mean temperatures, varied with time of day; and men and women exhibited comparable thermal variability. Our data corroborated Wunderlich's in that mean temperature varied diurnally, with a 6 AM nadir, a 4 to 6 PM zenith, and a mean amplitude of variability of 0.5 degrees C (0.9 degrees F); women had slightly higher normal temperatures than men; and there was a trend toward higher temperatures among black than among white subjects. CONCLUSIONS: Thirty-seven degrees centigrade (98.6 degrees F) should be abandoned as a concept relevant to clinical thermometry; 37.2 degrees C (98.9 degrees F) in the early morning and 37.7 degrees C (99.9 degrees F) overall should be regarded as the upper limit of the normal oral temperature range in healthy adults aged 40 years or younger, and several of Wunderlich's other cherished dictums should be revised.

Adult↗
PubMed1992

Epidural analgesia in labor and fetal hyperthermia.

OBJECTIVE: To assess the effect of epidural analgesia on fetal temperature in labor, contrasting intrauterine with oral thermometry. METHODS: Fetal skin and maternal uterine wall temperatures were measured with an intrauterine probe in 57 laboring women at term. Maternal oral temperatures were measured in the normal way by birth attendants unaware that their measurements would be examined. Maximum recorded fetal, uterine, and oral temperatures were compared. RESULTS: Epidural analgesia resulted in a significant fetal temperature rise compared with other methods of analgesia. Duration of epidural analgesia correlated with the fetal temperature (R = 0.44, P = .012). Oral thermometry underestimated fetal temperature in 95% of the studies. CONCLUSIONS: We estimate that 5% of fetuses reached a core temperature in excess of 40C in this study, all in association with epidural analgesia. We suggest that antipyretic measures be considered after 5 hours of epidural analgesia in ambient temperatures above 24C.

Analgesia, Epidural↗
PubMed2003

[Usefulness of monitoring forehead deep-tissue temperature as an index of core temperature in adult patients undergoing laparotomies under general anesthesia--investigation in operating rooms with air-movement control system using vertical flow].

BACKGROUND: Acute changes in air temperature in the vicinity of the patents' forehead may impair clinical usefulness of the forehead deep-tissue thermometry. We thus investigated usefulness of monitoring the forehead deep-tissue temperature as an index of core temperature in 12 adult patients undergoing laparotomies in operating rooms with air-movement control system using vertical flow. METHODS: Nasopharyngeal, forehead deep-tissue, palm deep-tissue, and fingertip skin-surface temperatures were recorded during surgery every 5 minutes in operating rooms where room temperature was thermostatically controlled at approximately 25 degrees C. The patients were not actively warmed with forced-air warmers, but covered with cotton blankets where possible. The deep-tissue and fingertip skin-surface temperatures were compared with the nasopharyngeal temperature using regression and Bland and Altman's analyses. RESULTS: The four temperatures continued decreasing during surgery, and the nasopharyngeal temperature decreased to below 36 degrees C 2 hours after induction of anesthesia. Only the forehead deep-tissue temperature satisfactorily correlated with the nasopharyngeal temperature (r = 0.76, n = 300, P < 0.0001). The difference between nasopharyngeal and forehead temperatures was +0.26 degree C, and its standard deviation was 0.34 degree C. CONCLUSIONS: The forehead deep-tissue temperature has sufficient accuracy and precision for clinical use in operating rooms with air-movement control system using vertical flow. However, the core temperature appears to be slightly underestimated with the forehead deep-tissue thermometry.

Adult↗