Showing papers on "Thermography published in 1976"

The aerial use of an infrared camera in a police search for the body of a missing person in New Zealand.

Abstract: An infrared camera operating in the spectral range of 2μm–5·6μm was fitted into a Royal New Zealand Air Force Iroquois helicopter and used to assist in a police search for the body of a missing hitchhiker. Although unsuccessful in its main purpose, it was well demonstrated that the aerial use of the infrared camera and equipment can locate points of interest unnoticed by ground searchers and thus decrease the ground search area. Subsequent tests revealed that the body of a dead animal could easily be detected seventeen days after burial.

Infrared thermography for determining equipment temperatures in oil well fires

Abstract: Infrared thermography is applied to the determination of the temperatures of equipment engulfed in an oil well fire. Operation is similar to a television camera in that the radiant flux from the scanner impinging on the infrared detector generates an electrical signal across the scanner. The amplitude of the signal varies according to the point-by-point temperature variation along the surface of the object that is being scanned by the camera. In this manner, a thermal picture display is generated by the signal produced by the scanning system. This produces a real time thermal image on the display screen. The thermal image is made stable, and hence usable in analyzing oil well fires, by the use of specially selected bandpass infrared filters.

Improved liquid cholesterol ester crystal thermography of the breast

Abstract: The infrated detection apparatus used in breast thermography is relatively costly and therefore is not widely available to less populated areas in the country. The use of liquid cholesterol crystals, applied to the breast (applied over a water-base black dye) has already been described in the literature as an effective substitute for infrared instrument thermography. This method, however, has been hampered by the time and troublesome effort necessary for removal of the substances upon completion of the study. The object of this study was to devise a feasible method of cutaneous breast thermography using liquid cholesterol esters, as in prior studies, but by applying them to an easily removable black base. As a result the length of the examination has been shortened, and patients have found the examination to be aesthetically more acceptable. With this improved method, liquid crystal thermography of the breast (and other areas) should become more widely applicable.

The effect of external pressure on skin temperature distribution by thermography.

Abstract: 1) Serial thermograms were taken after the application of various intensities and durations of localized pressure on the medial surface of the human forearm. 2) Thermal response of the body surface to localized pressure was quantified. 3) It was found that usually a time period of between 1 to 3 minutes elapsed before the body surface attained a maximum elevation of temperature from the time the localized pressure is removed. 4) It was found that increased intensity of pressure (5 psi vs. 3 psi) and longer duration (20 minutes vs. 10 minutes) caused larger thermal responses. 5) It is suggested that high resolution medical thermography may eventually become a useful tool in the fitting of prosthetic and orthotic devices and for the prediction of pressure sores formation so prophylactic measures can be started immediately on immobilized patients.

Thermography of the testicle. Preliminary study

Abstract: The preliminary study is concerned with 25 cases that have been examined using thermography in planes to check the conditions of temperature of the testes in normal and pathological states. Normal testicular thermography is characterised by a symmetrical and constant thermographic picture, the temperature staying between 32.5 and 34.5 degrees. In the pathological states of oligoasthenospermia plate thermography shows up a particular thermic picture associated with a varicocoele whether this is clinical or subclinical. The picture is one of hyperthermia and lack of symmetry in the case of a unilateral lesion. In these cases tyeing off the spermatic vein shows a rapid return to a normal thermographic picture. These positive results have led to a more extensive and deep study which is at present in progress.

A Passive Thermal Screen for Infrared Scene Simulation

Abstract: The objective of the investigation described here was to determine the feasibility of an infrared (8-14 pm) scene simulation concept; the concept is called a PTS (Passive Thermal Screen). It is passive because it does not contain any heat generating elements, but receives its energy from a visible image that is cast upon its working surface by a slide (or motion picture) projector, instead. Measurement data presented show that thermal contrasts of up to 16 C can be produced using bar pattern images and an input irradiance of 0.09 W/cm2. Contrast and temporal response measurements were made using a Thermo-vision infrared imaging camera (and display) in combination with a magnetic-disc recorder. The most severe problem area that remains before the concept can be put to practical use as part of a full-scale IR simulator is that of producing input slides that can accommodate the high radiance levels required of the projector.

Thermographic Imaging At Millimeter And Centimeter Wavelengths

Abstract: Theoretical considerations and experiments show that thermography at centimeter wavelengths offers an attractive penetration depth of more than one centimeter; however it is not well suited for remote imaging of the temperature of the human body because of its marginal spatial resolution and the required large distance between the receiver and the object. Millimeter wave thermography tests around 45 GHz show that a spatial resolution of a few millimeters and a temperature resolution of 0.1°K can be achieved. A penetration depth of several millimeters makes millimeter wave thermography more attractive for remote temperature sensing of deeper lying body tissues than infrared thermography.© (1976) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Detection Of Mine Hazards With Infrared Imagers

Abstract: Infrared imagers have been used to remotely sense several potentially hazardous conditions in mining operations; among these are loose rock, misfires, shorted power cables, overheated bearings, and combustion (both existing and incipient). In addition, the potential use of infrared imagers as mine rescue tools has been evaluated.

Thermography in differential diagnosis of lymphostasis in the lower limbs

Abstract: The authors report the data concerning the use of lymphography and thermography with the purpose of establishing the differential diagnosis in 42 patients with edema of the lower limbs of a different origin. A comparative estimation of different methods of the differential diagnosis indicated the advantages of infra-red thermography.

Results Of Ratio Temperature Thermography

Abstract: Our present understanding of breast cancer indicates that increased metabolic activity occurs and thus produces a local temperature increase. This paper evaluates present thermographic techniques used to detect these temperature increases and examines the problem of skin emissivity variations that can produce erroneous temperature measurements. These false temperature variations are on the order of the decision level used by radiologists, and therefore they can cause significant confusion in the interpretation of the thermogram. The ratio temperature thermograph is shown to reduce the effects of emissivity by measuring the spectral radiance at two prescribed wavelengths and ratioing the results. A dual-channel ratio thermo-graph was built using state-of-the-art detectors and electronics to prove its feasibility. The ratio temperature thermograph was quantitatively evaluated for small emissivity variations. This evaluation demonstrated the instrument's capability of minimizing emissivity effects. It was also evaluated for the detection of temperature changes.© (1976) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Thermo graphy apparatus

Abstract: PURPOSE:To make it possible to record (image signals obtained by optical scanning method with thermography apparatus) in VTR without using scan converter.

High Resolution IR Thermal Imaging For Electronic Inspection

Abstract: Advances in technology have brought about IR thermal imaging systems with faster scan times and higher spatial resolution. This is in part due to the use of the mercury cadmium telluride (HgCdTe) detector which provides system performance advantages in evaluating temperatures up to 200°C. High spatial resolution permits the detection of thermal gradients in small electronic components and can reveal small voids and defects in materials. Thermal profiling of electronic circuit boards can be used for design evaluation and production testing. Effective use of this technique should take into consideration variations in emissivity of the material being studied. Examples of how to correct or compensate for these emissivity variations will be presented. Detection of voids and flaws in materials often requires the application of heat or cold to the material being investigated. This produces a surface thermal gradient which depicts the underlying abnormality. Approaches to the use of this technique in void detection will be presented.

Thermography in the Investigation of Breast Cancer

Abstract: The fundamental concept used in thermography is that skin temperature abnormalities are manifestations of underlying pathology. This has “been known since the earliest days of medicine — Hippocrates was aware of the high left-right symmetry of skin temperature in the human body. Until recently, skin temperature had to he estimated by touch — this is still a good method; in good circumstances the hand can detect 1 C differences in skin temperature. Accurate spot temperature readings can now be made with thermocouples, thermistors or with radiometers. The next step — the presentation of an image of skin temperature distribution — was greatly assisted by funds injected into the military aspects of temperature displays.

Transfer thermography: some possible medical applications

Abstract: In Atsumi's well-known book, Medical Thertnography (1), there 1s a thermogram of \"a recently occupied bed\" and another of \"the same bed thlrty tes later.\" The shape of the departed occupant's body 1s revealed clearly by the thermal Image In the first picture and is still falntly visible In the second. The Image being examined i s a \"transfer\" of the thermal pattern of the former occupant's body surface to the mattress. For this reason we have termed examinatlon of such patterns äs \"transfer thermography\" äs opposed to a direct thermography of the surface In questlon.