FR2516779A1 - Flexible thermographic film for scanning body surface temps. - with multiple liquid crystal layers for thermal and spatial discrimination - Google Patents

Abstract

A flexible heat sensitive film for thermal scanning of local body heat distribution, e.g. for thermal screening of breasts for overheated inclusions, incorporates several superimposed layers of liquid crystal arrays each sensitive to a slightly different temperature range within a span of pref. 24-35 deg.C. Pref. the liquid crystal layers are printed in sets of systematic offset arrays offering four contrasting colours, to provide clear thermogerm contours for the form of the bust relative to the body of the subject. Improves the sensitivity and resolution of thermal differentials better than conventional monolayer thermographic drape films. Pref. the base layer is responsive to the range 24-27 deg.C. and the other layers offer discrimination of about 1 deg.C., about a mean temp. corresponding to that of surface skin. The film pref. has covers of plain transparent polyester or other plastic film typically 10-40 microns thick.

Description

 The invention relates to a flexible thermosensitive sheet with accentuating contours for anatomical contact thermography, for example breast thermography.

 On current thermographic images by using flexible thermosensitive sheets, the outline of the breast appears slightly marked so that the exact location of the anomalies does not always prove to be correct.

 To this difficulty are added other factors of imprecision making interpretation not immediate and, sometimes, questionable.

 These difficulties are largely due to the technical composition and quality of certain sheets, but also to the lack of information and references that the image could provide.

 The object of the invention is to remedy this drawback by proposing a flexible heat-sensitive sheet with accentuation of the contours on which the breast line appears, in a precise and perfectly contrasted manner, and which provides an immediate indication of the quality of the contact.

 This sheet will allow you to easily and quickly visualize and locate all detectable anomalies.

 In addition, the appearance of the contour will be a sign of a good application, that is to say of correct contact.

The imprecision on the edges disappears and the usual uncertainty between the cold zone and the mauyaise application no longer exists.

To this end, the heat-sensitive sheet according to the invention is remarkable for the following composition:
A thermosensitive base layer with a sensitive formulation between 24 and 270 ° C. and a thermographic layer with offset sensitivity zones and with a shared end range covering the range from 28 to 350 ° C., each formulation having a variation in four colors.

Other characteristics and advantages of the invention emerge from the description below, given by way of non-limiting example on an embodiment, with reference to the accompanying drawing in which
The Li-1 figure 1 is a schematic sectional view of the sheet
thermographic according to the invention, illustrating its composition Figure 2 is a schematic plan view it polishing
a type of arrangement in lateral succession of differences
your formulations of the thermographic layer.

 The flexible composite thermographic sheet according to the invention provides the perfect visualization of the contours sought by practitioners. It facilitates the interpretation of thermograms and makes it possible to quickly locate anomalies. It provides an indication of the quality of the contact. Therefore, the thermogram carries additional information useful in the application of localized treatment.

 The thermographic sheet consists of a plastic support 1 of the plastic or polyester film type 10 to 40 microns thick, a thermosensitive base layer 2 with an area of sensitivity extended between 240 ° C. and 270 ° C., a layer thermographic 3 -and a flexible transparent upper protection 4, for example a plastic or polyester film.

 The layer of. background 2 is, for example, in the form of a thin homogeneous thickness of a composition of liquid crystal formulations allowing the visualization of a single color in the temperature range 240C - 27 C. It is in saturated state at skin surface temperatures.

 The thermographic layer 3 is composed of several networks 5, 6, 7, etc. of crystalline deposits woven, offset or nested in a regular geometric pattern.

Each deposit corresponds to a given formulation with four colors red brown - yellow - green - blue, whose variation range extends over, for example, one degree within each elementary variation zone, within a variation range overall covering I nterva II e of temperatures 280C - 350C. The elementary zones of variation overlap at the end so as to constitute a continuous variation over the entire amplitude of the sensitivity zone. These elementary zones cover for example an amplitude of one degree.

 The thickness of the crystal layers depends on the film chosen and the strength sought.

 The manufacturing process uses the techniques of screen printing and the process of air knives in a climatic chamber at precise, regular temperature, humidity and air speed conditions.

 The evaporation of water during drying is rigorously controlled in an enclosure, for example connected to the condenser of a heat pump.

 The repetitive geometric pattern chosen may, for example, be that shown in FIG. 2 according to patterns or groupings of several formulations in straight and oblique linear repetition.

 The sheet according to the invention makes it possible on the one hand to visualize the contours and, on the other hand, to bring out the warmer zones in anomaly (hyperthermic zones) or in reference (vein).

 It also serves to indicate the quality of the contact: the appearance of the contour is a sign of correct contact.

 Furthermore, the precision of the sheets is increased sufficiently to be able to use the color limits as isothermal curves.

 By multiplying the formulations, we could further increase the precision.

 The sheet according to the invention provides breast thermography with precious help which will classify it in another category than that of the means of prior investigation.

 Although the invention has been described in connection with a particular embodiment, it cannot be limited to the strict framework of the description. Different variations without inventive contribution: substitution by equivalent means, direct derivatives, addition of inoperative elements and other modifications of a secondary order, on the contrary fully fall within the spirit of the invention and cannot escape its protection.

Claims (9)

 1. Flexible composite thermosensitive sheet with accentuation of contours and contrasts, characterized in that it consists of a flat film support (1), a base layer (2) of liquid crystals of saturated formulation at the temperature of the skin, of a thermographic layer (3) in several formulations of liquid crystals, with zones of elementary variations offset so as to cover a range of global variation extended on either side of an average temperature and disjoint from that of the base layer, the thermographic layer being covered with a transparent thermographic film.  2. Sheet according to claim 1 characterized in that the elementary zones of variation of each formulation of the thermographic layer (3) overlap at the end.  3. Sheet according to claim 1 characterized in that the formulation of the base layer (2) has a variation zone between 240C and 27 C.  4. Sheet according to claim 1 characterized in that the overall variation range of the thermographic layer (3) extends from 28 to 350C.  5. Sheet according to claim 1 characterized in that the elementary zones of variation of each formulation of the thermographic layer (3) each extend over 10C.  6. Sheet according to claim 1 characterized in that the average temperature is the surface temperature of the breast.  7. Sheet according to claim 1 characterized in that the liquid crystal formulations of  the thermographic layer (3) are nested in networks.  8. Sheet according to claim 7 characterized in that the networks have a succession of regular patterns.  9. Sheet according to claim 1 characterized in that each formulation of the thermographic layer (3) has a variation on four colors.