Biological fluid measuring device

Claim 2

A biological fluid measuring device comprising: (a) a main housing including electronic circuit means and at least two electrodes; and (b) a cartridge having a membrane and being removably mounted on the housing with the membrane operably associated with the electrodes, the cartridge including means for protecting the membrane when not in use.

Claim 3

The biological fluid measuring device of claim 1 wherein the cartridge includes a body portion retaining the membrane and the protection means includes a cover movably mounted on the body portion.

Claim 4

The biological fluid measuring device of claim 2 wherein the cartridge includes a hinge for mounting the cover on the body portion.

Claim 5

The biological fluid measuring device of claim 2 wherein the body portion and membrane define a well having sides and a bottom with the bottom being defined at least in part by the membrane.

Claim 6

The biological fluid measuring device of claim 4 wherein the well has a volume of less than about 0.2 cubic centimeters and is adapted to accept a sample as small as about 5 microliters.

Claim 7

The biological fluid measuring device of claim 1 wherein the protection means seals the membrane from ambient air.

Claim 8

The biological fluid measuring device of claim 6 wherein the protection means includes a flexible gasket.

Claim 9

The biological fluid measuring device of claim 1 further including retaining means for releasably retaining the cartridge on the housing.

Claim 10

The biological fluid measuring device of claim 8 wherein the retaining means includes a detent on the cartridge that is received in a recess defined by the housing.

Claim 11

The biological fluid measuring device of claim 1 wherein the housing defines a base surface with the electrodes projecting upwardly from the base surface.

Claim 12

The biological fluid measuring device of claim 10 wherein the membrane is stretched over and in contact with the electrodes.

Claim 13

The biological fluid measuring device of claim 1 wherein the membrane includes a first layer of a nonporous block copolymer having hydrophobic segments and hydrophilic segments that limits the amount of the substance passing therethrough, a second layer of a nonporous block copolymer including an enzyme bound to the first layer, said enzyme reacting with the substance to form a product, and a third layer of a nonporous block copolymer having hydrophobic and hydrophilic segments that is bound to the second layer and covering the surfaces of the electrodes that restricts the passage of the substance therethrough but permits the passage of the product whereby the amount of product formed corresponds to the amount of the substance in the sample.

Claim 14

A biological fluid measuring device comprising: (a) a case having an upper portion and a lower portion together defining a cavity, the upper portion also defining a recessed cell having a base surface; (b) at least two electrodes mounted on the upper portion of the case and extending upwardly from the base surface; (c) electronic circuit means carried by the case within the cavity and operably associated with the electrodes for processing a signal from the electrodes; (d) display means carried by the case and operably associated with the electronic circuit means for displaying a result; and (e) a cartridge having a body portion defining a receiving surface, the cartridge also including a membrane mounted on the receiving surface and a cover movably mounted on the body portion, the body portion being removably mounted in the recessed cell of the upper portion of the case with the membrane operably associated with the electrodes.

Claim 15

A biological fluid measuring device comprising: (a) a case having an upper portion and a lower portion together defining a cavity, the upper portion also defining a recessed cell having a base surface; (b) at least two electrodes mounted on the upper portion of the case and extending upwardly from the base surface; (c) electronic circuit means carried by the case within the cavity and operably associated with the electrodes for processing a signal from the electrodes; (d) display means carried by the case and operably associated with the electronic circuit means for displaying a result; and (e) a cartridge having a body portion defining a receiving surface, the cartridge also including a membrane mounted on the receiving surface and a cover movably mounted on the body portion, the body portion being removably mounted in the recessed cell of the upper portion of the case with the membrane operably associated with the electrodes.

Claim 16

The biological fluid measuring device of claim 13 wherein the cartridge includes a hinge which movably mounts the cover on the body portion.

Claim 17

The biological fluid measuring device of claim 13 wherein the body portion and membrane define a well that is adapted to receive the biological fluid.

Claim 18

The biological fluid measuring device of claim 13 including an electrically nonconductive support material about the electrodes, the electrodes and electrically nonconductive support material defining a membrane contact surface.

Claim 19

The biological fluid measuring device of claim 16 wherein the membrane is stretched over the membrane contact surface.

Claim 20

The biological fluid measuring device of claim 13 including a gasket about the well cooperating with the body portion and cover to seal the well from ambient air.

Claim 21

The biological fluid measuring device of claim 13 wherein the electrodes are carried by a post mounted on the upper portion of the case and extending upwardly from the base surface.

Claim 22

The biological fluid measuring device of claim 19 wherein the body portion includes a collar which extends about the post, the membrane being attached to the collar.

Claim 23

The biological fluid measuring device of claim 19 wherein the post includes an electrically nonconductive support material about the electrodes to retain the electrodes in a fixed position.

Claim 24

A biological fluid measuring device comprising: (a) a case defining a cavity; (b) at least two electrodes mounted on the case; (c) electronic circuit means carried in the cavity and operably associated with the electrodes for processing a signal from the electrodes; (d) display means carried by the case and operably associated with the electronic circuit means; (e) a body portion defining an opening being removably mounted on the case; (f) a membrane mounted on the body portion and being operably associated with the electrodes, the membrane and opening together defining a well; and (g) a cover movably mounted on one of the case and body portion, the cover having a first position which permits access to the well and a second position which protects the well from the ambient surroundings.

Claim 25

A biological fluid measuring device comprising: (a) a case defining a cavity; (b) at least two electrodes mounted on the case; (c) electronic circuit means carried in the cavity and operably associated with the electrodes for processing a signal from the electrodes; (d) display means carried by the case and operably associated with the electronic circuit means; (e) a body portion defining an opening being removably mounted on the case; (f) a membrane mounted on the body portion and being operably associated with the electrodes, the membrane and opening together defining a well; and (g) a cover movably mounted on one of the case and body portion, the cover having a first position which permits access to the well and a second position which protects the well from the ambient surroundings.

Claim 26

The biological fluid measuring device of claim 22 including a gasket carried by one of the cover and body portion for sealing with the cover and body portion to protect the well when the cover is in its second position.

Claim 27

A cartridge for use as part of a biological fluid measuring device having a housing carrying electronic circuit means and at least two electrodes, the cartridge comprising: (a) a body portion having a side wall defining an opening; (b) a membrane mounted on the body portion across the opening, whereby the sidewall and membrane together define a well; (c) means for mounting the body portion on the housing with the membrane operably associated with the electrodes; and (d) a cover movably mounted on the body portion and having a first position which permits access to the well and the second position which protects the well from the ambient surroundings.

Claim 28

A cartridge for use as part of a biological fluid measuring device having a housing carrying electronic circuit means and at least two electrodes, the cartridge comprising: (a) a body portion having a side wall defining an opening; (b) a membrane mounted on the body portion across the opening, whereby the sidewall and membrane together define a well; (c) means for mounting the body portion on the housing with the membrane operably associated with the electrodes; and (d) a cover movably mounted on the body portion and having a first position which permits access to the well and the second position which protects the well from the ambient surroundings.

Claim 29

The cartidge of claim 24 further including a hinge for movably mounting the cover on the body portion.

Claim 30

The cartridge of claim 24 further including a gasket and cooperating with the cover and body portion to seal the well from the ambient surroundings when the cover is in its second position.

Claim 31

The cartridge of claim 26 wherein the gasket is carried by the body portion and extends about the well, and the cover includes a ring which engages the gasket when the cover is in its second position.

Claim 32

The cartridge of claim 24 wherein the body portion includes a collar opposite the well with respect to the portion of the membrane which defines the well, the membrane being attached to the collar.

Claim 33

The cartridge of claim 24 wherein the body portion includes at least one wing which engages a slot defined by the housing.