Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Thermometry”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 289 records · Page 16Linked to original sources
PubMed2001

Clinical thermometry, using the 27 MHz multi-electrode current-source interstitial hyperthermia system in brain tumours.

BACKGROUND AND PURPOSE: In interstitial hyperthermia, temperature measurements are mainly performed inside heating applicators, and therefore, give the maximum temperatures of a rather heterogeneous temperature distribution. The problem of how to estimate lesion temperatures using the multi-electrode current-source interstitial hyperthermia (MECS-IHT) system in the brain was studied. MATERIALS AND METHODS: Temperatures were measured within the electrodes and in an extra catheter at the edge of a 4 x 4 x 4.5 cm(3) glioblastoma multiforme resection cavity. From the temperature decays during a power-off period, information was obtained about local maximum and minimum tissue temperatures. The significance of these data was examined through model calculations. RESULTS: Maximum tissue temperatures could be estimated roughly by switching off all electrodes for about 5 s. Model calculations showed that the minimum tissue temperatures near a certain afterloading catheter correspond well with the temperature of the applicator inside, about 1 min after this applicator was switched off. CONCLUSIONS: Although the electrode temperatures read during heating are not suitable to assess the temperature distribution, it is feasible to heat the brain adequately using the MECS-IHT system with extra sensors outside the electrodes and/or application of decay methods.

Brain Neoplasms↗
PubMed1985

Liquid crystal thermometry for continuous temperature measurement in emergency department patients.

A single temperature measurement recorded on admission to the emergency department provides no information about temperature alterations occurring during the course of evaluation. Continuous monitoring of patients' temperatures in the ED, however, may alter management and decrease morbidity. Our study evaluated the reliability of liquid crystal thermometers (LCTs) and the clinical benefit of continuous temperature monitoring in the ED. Commercially available LCTs (corrected 4 degrees F to reflect core temperature) were applied to the foreheads of randomly selected patients. Serial oral electronic thermometer readings were compared to those obtained by LCT. Fever was defined as a temperature higher than 99.5 F orally or 100 F by LCT. One hundred two patients underwent simultaneous LCT and oral temperature measurements, with a correlation coefficient of 0.661. Hypothermia was not encountered. Eighty-four patients were afebrile, and 18 were febrile by oral measurement on admission. Of the afebrile patients, 13 (15.5%) became febrile while in the ED. The temperature course was identified correctly by LCT in 83.3% of cases. The LCT correctly identified all patients who were febrile on admission, as well as 92.3% of those who developed fever while in the ED. The latter fevers would have been missed by routine single-temperature determination on ED admission. Detection of fever stimulated more aggressive clinical evaluation of these patients. Eight of nine patients who defervesced in response to antipyretic therapy were identified correctly by LCT.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed2003

Hyperthermia induces T1 relaxation and blood flow changes in tumors. A MRI thermometry study in vivo.

Regional hyperthermia in combination with chemotherapy and/or radiotherapy has proven to be an effective treatment concept for locally advanced deep-seated tumors. Simultaneous MR-imaging could be a promising approach for therapy optimization. Purpose of this study was the in vivo investigation of temperature induced longitudinal relaxation time (T(1)) and blood flow changes in a tumor model. Using a 1.5 Tesla MR system, the T(1) sensitivity on temperature and the onset of tissue changes at temperatures >44 degrees C were investigated in muscle samples. Also, fourteen Syrian Golden Hamsters with amelanotic melanoma A-MEL-3 were examined during heating of the tumors. Temperature induced blood flow and T(1) changes were determined continuously during hyperthermia. Changes of T(1) correlated linearly with temperature over a wide range (27-44 degrees C) in the tissue sample. Tissue changes became notable above 44 degrees C. In the tumor model, relative changes of T(1) (unlike blood flow) showed linear correlation with temperature over the entire range of hyperthermia relevant temperatures (32-44 degrees C). For a low thermal dose, T(1) allows the assessment of temperature changes in tumors in vivo. At higher thermal doses, in addition to temperature changes, T(1) also shows tissue changes. Both temperature and tissue changes supply important information for hyperthermia.

Animals↗
PubMedDate not supplied

Monitoring neuropathic ulcer healing with infrared dermal thermometry.

The purpose of this study is to prospectively evaluate skin temperatures at the site of neuropathic ulceration before, during, and after wound healing using the contralateral extremity as a physiologic control and to evaluate variables that may influence skin temperature gradients. We studied 17 male and 8 female diabetics with mean age and duration of diabetes of 52.4 +/- 11.6 years and 13.8 +/- 7.8 years with grade I (Meggitt-Wagner) plantar ulcers. All patients received weekly cast changes with wound and skin temperature assessments. After healing, all patients were fitted with prescription shoe gear. Temperatures on the ulcerated foot were higher than those on the contralateral foot on initial presentation (91.1 vs. 84.2 degrees F, t = 8.9, p < 0.0001, 95% Cl 5.3 to 8.5), but the same following healing. Patients with vibration perception thresholds greater than 45 V had wider skin temperature gradients than those with lesser degrees of sensory neuropathy (8.8 +/- 4.1 vs. 4.9 +/- 2.5 degrees F, p = 0.007). Additionally, subjects with toe brachial indices below 0.60 had greater skin temperature gradients at the site of ulceration than those with higher indices (9.4 +/- 4.0 vs. 5.8 +/- 3.4 degrees F, p = 0.01). There was not a significant difference in initial skin temperature gradients by duration of wound prior to treatment, duration of wound healing, sex, maximum plantar pressure, or hemoglobin A1C level.

Adult↗
PubMed1993

Spatially resolved temperature measurements in electrophoresis capillaries by Raman thermometry.

Local temperatures inside a 75-microns-i.d. capillary under electrophoresis conditions are measured noninvasively with a Raman microprobe. The method is based on the temperature dependence of the water O-H stretch equilibrium between weakly bent and strongly bent hydrogen bonded species. With calibration against a known temperature standard, this technique is shown to be capable of obtaining spatially resolved intracapillary temperature measurements with an accuracy of +/- 1.0 degree C and a precision of +/- 0.1 degree C. Intracapillary temperatures ranging from 25 to 70 degrees C are observed over the range of buffer compositions and electric fields used. Differences between local temperatures and average capillary temperatures are observed at all operating conditions. The difficulty of an accurate theoretical description of heat dissipation under CE conditions is discussed.

Electrophoresis↗