This usually means having no relatives. Perhaps it is relating to a patient in hospital? Otherwise I do not know a medical machinery meaning. Perhaps others have a suggestion here.

"Bix" seems to be a trademark, whose English equivalents are as follows:
common name:oil of wintergreen, betula oil
chemical name: Methyl salicylate

Methyl salicylate (chemical formula C6H4(HO)COOCH3; also known as salicylic acid methyl ester, oil of wintergreen, betula oil, methyl ester) is a natural product of many species of plants. Some of the plants producing it are called wintergreens, hence the common name.

Methyl salicylate is toxic if taken internally in large amounts, and plants containing it probably evolved it as an anti-herbivory defence. Numerous plants produce methyl salicylate in very small amounts. Plants producing it in significant amounts (readily detected by scent) include:

Most species of the family Pyrolaceae, particularly those in the genus Pyrola.
Some species of the genus Gaultheria in the family Ericaceae.
Some species of the genus Betula in the family Betulaceae, particularly those in the subgenus Betulenta.
Structurally, it is methylated salicylic acid. Commercial methyl salicylate is now synthesized from salicylic acid, but in the past, it was commonly distilled from the twigs of Sweet Birch (Betula lenta) and Eastern Teaberry (Gaultheria procumbens).

It is used as an ingredient in deep heating rubs, and in small amounts as a flavouring agent. It also has the property of fluorescence, converting ultraviolet light into visible blue light.

It can be produced from the condensation reaction of Salicylic Acid and Methanol


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Note added at 1 day 1 hr 12 mins (2005-09-09 07:09:53 GMT)
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I've searched for the word "bix" everywhere, including "Dorland Dictionary of Medicine), and I asked a friend of mine, who is a doctor; but there exists no such a word in Persian nor in English. I belive it should be "vix" (misspelled as "bix" in your Farsi text). "Vix" is the commonly-used Farsi name for "Methyl salicylate" (see: dokhtarbass.blogspot.com/2005/06/blog-post.html , naarenj8.persianblog.com/1382_8_naarenj8_archive.html)

Medium and/or small should refer to the size of the tubes containing "vix" or in English "oil of wintergreen/betula oil/Methyl salicylate".

I cannot read the farsi accompanying the question, and am not sure if the x is pronounced as ks or as kh, but in the case of a pharyngeal h I believe the answer may be 'socket', at least this is how the word is used in Dari, eg cheshmesh az bikh keshidam (I pulled his eye from the socket). I don't know what medical instrument would be referred to as a small or medium socket, but this is my best guess.