Smarty pants

 作者:于钡     |      日期:2019-03-07 10:17:03
By Barry Fox THE next revolution in panty liners will be ones that change colour to warn women they are about to ovulate. They can also tell if a woman has an infection–or even when her period will start. Healthcare companies are scrambling to patent the new approach first. In the early 1990s, Media-Pharma of Germany, Kimberly-Clark of Wisconsin and several private inventors separately filed patents on the idea of impregnating sanitary towels and diapers with chemicals that changed colour according to the concentration of glucose and nitrites in blood and faeces. Now Procter & Gamble, maker of Always and Tampax, has filed a string of world patents. They detail how in tests women wore panty liners impregnated with gum guaiac wood resin, which turns blue in the presence of tiny traces of blood, and a pH sensor such as carminic acid, which turns red between pH 4 and 7. These markers turn purple four hours ahead of menstruation, giving the wearer plenty of notice. The panty liner that pinpoints ovulation has a plastic film coated with amorphous silicon that changes thickness slightly in response to changes in the levels of oestrogen, progesterone and follicle-stimulating hormones. The thickness change alters the path of reflected light to create a purple spot on a gold background. P&G’s patents also say they will be able to test for pregnancy and detect substances which signal bacterial, fungal and viral infection, including Escherichia coli, Salmonella, thrush, Chlamydia and HIV. Canadian and South African researchers are also developing disease detecting sanitary wear–but these need to be analysed in a lab (New Scientist, 30 September 2000, p 19). When these products will reach the supermarket shelf is unclear. P&G’s Sally Woodage would only say: