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Journal ArticleDOI

A Liquid-Crystal Contact-Lens Device for Measurement of Corneal Temperature

01 Sep 1973-IEEE Transactions on Biomedical Engineering (IEEE)-Vol. 20, Iss: 5, pp 387-388
TL;DR: Development of a thermally sensitive contact lens consisting of a laminated liquid-crystal layer that presents a novel approach to the noninvasive in vivo measurement of comeal surface temperatures.
Abstract: Development of a thermally sensitive contact lens consisting of a laminated liquid-crystal layer is described. This device, useful in a variety of applications, presents a novel approach to the noninvasive in vivo measurement of comeal surface temperatures.
Citations
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Journal ArticleDOI
TL;DR: In this paper, the authors briefly describe some historical developments made in the field of enzymatic fuel cells (FCs), discussing important design considerations taken when constructing mediator-, cofactor-, and membrane-less biological FCs (BFCs).

223 citations

Journal ArticleDOI
TL;DR: In this article, a wirelessly powered contact lens display was tested on live, anesthetized rabbits with no observed adverse effect, and the display can be powered wirelessly from ~1 m in free space and 2 cm in vivo on a rabbit.
Abstract: We present the design, construction and in vivo rabbit testing of a wirelessly powered contact lens display. The display consists of an antenna, a 500 × 500 µm2 silicon power harvesting and radio integrated circuit, metal interconnects, insulation layers and a 750 × 750 µm2 transparent sapphire chip containing a custom-designed micro-light emitting diode with peak emission at 475 nm, all integrated onto a contact lens. The display can be powered wirelessly from ~1 m in free space and ~2 cm in vivo on a rabbit. The display was tested on live, anesthetized rabbits with no observed adverse effect. In order to extend display capabilities, design and fabrication of micro-Fresnel lenses on a contact lens are presented to move toward a multipixel display that can be worn in the form of a contact lens. Contact lenses with integrated micro-Fresnel lenses were also tested on live rabbits and showed no adverse effect.

204 citations

Journal ArticleDOI
TL;DR: The literature was reviewed with regard to progress in human thermometry techniques, the parallel development in ocular temperature measurement, the current use of infrared imaging, and the applications of ocular thermography.
Abstract: Purpose. To review the evolution in ocular temperature measurement during the last century and examine the advantages and applications of the latest noncontact techniques. The characteristics and source of ocular surface temperature are also discussed. Methods. The literature was reviewed with regard to progress in human thermometry techniques, the parallel development in ocular temperature measurement, the current use of infrared imaging, and the applications of ocular thermography. Results. It is widely acknowledged that the ability to measure ocular temperature accurately will increase the understanding of ocular physiology. There is a characteristic thermal profile across the anterior eye, in which the central area appears coolest. Ocular surface temperature is affected by many factors, including inflammation. In thermometry of the human eye, contact techniques have largely been superseded by infrared imaging, providing a noninvasive and potentially more accurate method of temperature measurement. Ocular thermography requires high resolution and frame rate: features found in the latest generation of cameras. Applications have included dry eye, contact lens wear, corneal sensitivity, and refractive surgery. Conclusions. Interest in the temperature of the eye spans almost 130 years. It has been an area of research largely driven by prevailing technology. Current instrumentation offers the potential to measure ocular surface temperature with more accuracy, resolution, and speed than previously possible. The use of dynamic ocular thermography offers great opportunities for monitoring the temperature of the anterior eye. © 2005 Contact Lens Association of Ophthalmologists, Inc.

150 citations

Journal ArticleDOI
TL;DR: Ocular surface temperature is greater with hydrogal and greater still with silicone hydrogel contact lenses in situ, regardless of modality of wear and the effect is likely to be due to the thermal transmission properties of a contact lens.

102 citations


Cites background from "A Liquid-Crystal Contact-Lens Devic..."

  • ...Previous attempts at ocular temperature measurement have included scleral contact lens devices [6–8], thermistors directly into the fornix or cornea [4,9] and infrared bolometers [10–13], which record thermal radiation on a numerical dial....

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Book ChapterDOI
01 Jan 1984

85 citations

References
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Journal ArticleDOI
TL;DR: The purpose of this paper is to investigate the temperature differences that exist between right and left corneae and periorbital skin, and to determine if a constant thermal pattern exists in an individual at differing environmental temperatures over a period of time.
Abstract: WHILST the absolute value of a surface temperature may have intrinsic value as a measurement, it is of limited application since so many factors are involved in its formation. These include local blood supply, endogenous metabolism, environmental temperature, and the period of equilibration before measurement is made. In practice it is impossible to separate their various effects with any degree of certainty so that any interpretation given to an isolated surface temperature reading is of doubtful value. This contrasts with the measurement of a relatively constant temperature such as that of the body core, since here deviations from normality can be readily detected. However, in man, as surface anatomical symmetry exists about a median plane the temperature of cornea or skin on one side of this plane can be compared with that of a contralateral area and any deviation from normality detected. This pre-supposes that the normal temperature difference has been established and such an assumption is implicit in the literature on surface temperature measurement (e.g. Lawson, 1957; Williams, Williams, and Handley, 1960,1961; Lawson and Chughtai, 1963; Barnes, 1963; Barnes and Gershon-Cohen, 1963; Gershon-Cohen, Berger, Haberman, and Barnes, 1964; Wood, 1964, 1965; Heinz, Goldberg, and Taveras, 1964; Cosh, 1966; Cosh and Ring, 1967), it being assumed that this anatomical symmetry produces a thermal symmetry as between right and left sides. The quantitative data in support of this is scanty; Williams and others (1961) assume a difference of greater than 1°C. over breast lesions to be abnormal but no evidence is given; Gerhson-Cohen and others (1964) also use this figure but state that after sufficient studies have been made some other figure may be found more appropriate (in distinguishing benign from malignant conditions in the breast); Cosh (1966) mentions and illustrates the thermal symmetry of the hands giving actual temperatures measured, but this paper is mainly concerned with sequential measurements and not differences; Heinz and others (1964) assume a difference of 1°F. between the right and left halves of the head but offer no evidence in support; only Wood (1965) attempts to establish a normal temperature difference-in this case for forehead skin. Using a Barnes thermograph on approximately 1,000 normal subjects, he found the average temperature difference between the two sides to be 0-5'F., but again only this statement is made and no further data are given. Areas of skin respond differently to changes in environmental and body core temperature according to their anatomical site (Fox and Edholm, 1963). Consequently, a normal difference over, say, breast skin need not necessarily be the same as that over forehead skin. The purpose of this paper is to investigate the temperature differences that exist between right and left corneae and periorbital skin, and to determine if a constant thermal pattern exists in an individual at differing environmental temperatures over a period of time.

37 citations