# US 11,441,977 B2 · Biological fluid dilution devices > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,441,977 B2 - Document ID: US11441977B2 - Status: Granted - Kind: B2 - Application number: 16/492,267 - Filed: 2017-04-03 - Published: 2021-03-18 - Granted: 2022-09-13 - Earliest claimed: 2017-04-03 - Assignees: Hewlett-Packard Development Company, L.P. - Applicants: Hewlett-Packard Development Company, L.P. - Inventors: Gary G. Lutnesky; Si-lam Choy - Web page: https://patentgrep.com/patent/US11441977B2 ## CPC - G01N 1/38: Diluting, dispersing or mixing samples - B01L 3/502: {with fluid transport, e.g. in multi-compartment structures} - B01L 2200/0605: Metering of fluids - B01L 2200/0684: Venting, avoiding backpressure, avoid gas bubbles - B01L 2300/046: Function or devices integrated in the closure - B01L 2300/069: Absorbents; Gels to retain a fluid - B01L 2400/0478: pistons - B01L 2400/0605: check valves - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) - B01L: CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE ## Abstract A biological fluid dilution device can include a syringe body including a diluent chamber at a front end of the syringe body and a piston tube at a rear end of the syringe body. The diluent chamber can be partially filled with a diluent fluid. A moveable piston can be slidably engaged in the piston tube and form a fluid-tight seal with an interior surface of the piston tube. The moveable piston can include a metering groove to contain a precise volume of a biological fluid between the metering groove and the interior surface of the piston tube. A biological fluid inlet on the piston tube can be capable of delivering the biological fluid to the metering groove. The moveable piston can be slidable toward to diluent chamber to introduce the biological fluid in the metering groove into the diluent chamber. ## Claims ### Claim 1 A biological fluid dilution device, comprising: a syringe body comprising a diluent chamber partially filled with a diluent fluid at a front end of the syringe body and a piston tube at a rear end of the syringe body leading into the diluent chamber; a moveable piston slidably engaged in the piston tube and forming a fluid-tight seal with an interior surface of the piston tube, wherein the moveable piston comprises a metering groove to contain a precise volume of a biological fluid between the metering groove and the interior surface of the piston tube; and a biological fluid inlet on the piston tube capable of delivering the biological fluid to the metering groove, wherein the moveable piston is slidable toward the diluent chamber to introduce the biological fluid in the metering groove into the diluent chamber. ### Claim 2 (depends on 1) The device of claim 1, further comprising a piston plunger lock engaged with the piston to constrain the piston in a position where the metering groove is aligned with the biological fluid inlet. ### Claim 3 (depends on 1) The device of claim 1, wherein the biological fluid inlet comprises a cap with an integrated pump for containing and pumping the biological fluid into the metering groove. ### Claim 4 (depends on 1) The device of claim 1, wherein the syringe body further comprises a vent port aligned with the biological fluid inlet to vent air from the metering groove. ### Claim 5 (depends on 4) The device of claim 4, further comprising an absorbent material in fluid communication with the vent port to absorb excess biological fluid from the vent port. ### Claim 6 (depends on 4) The device of claim 4, wherein the vent port comprises a capillary break to retain excess biological fluid in the vent port, the capillary break including a tapered portion and a narrowed opening with a smaller width than a width of the vent port. ### Claim 7 (depends on 1) The device of claim 1, wherein the metering groove includes a groove bottom surface formed of a first material and groove walls formed of a second material, wherein the first material has a higher surface energy than the second material. ### Claim 8 (depends on 1) The device of claim 1, further comprising a pressure check valve on the diluent chamber to release excess pressure in the diluent chamber. ### Claim 9 (depends on 1) The device of claim 1, further comprising a MEMS chip comprising a pump to pump diluted biological fluid from the diluent chamber and a sensor to measure a property of the diluted biological fluid. ### Claim 10 (depends on 9) The device of claim 9, further comprising an absorbent material into which the pump pumps the diluted biological fluid. ### Claim 11 (depends on 10) The device of claim 10, further comprising an enclosure containing the absorbent material, the enclosure including a vent port to the atmosphere in the form of a tortuous channel. ### Claim 12 A biological fluid dilution device, comprising: a syringe body comprising a diluent chamber partially filled with a diluent fluid at a front end of the syringe body and a piston tube at a rear end of the syringe body leading into the diluent chamber; a moveable piston slidably engaged in the piston tube and forming a fluid-tight seal with an interior surface of the piston tube, wherein the moveable piston comprises a metering groove to contain a precise volume of a biological fluid between the metering groove and the interior surface of the piston tube; a biological fluid inlet on the piston tube capable of delivering the biological fluid to the metering groove, wherein the moveable piston is slidable toward the diluent chamber to introduce the biological fluid in the metering groove into the diluent chamber; a MEMS chip comprising a pump to pump diluted biological fluid from the diluent chamber and a sensor to measure a property of the diluted biological fluid; and an absorbent material enclosure in fluid communication with the pump, the absorbent material enclosure containing an absorbent material to absorb diluted biological fluid pumped from the diluent chamber; wherein the syringe body further comprises a vent port aligned with the biological fluid inlet to vent air from the metering groove, wherein the vent port vents air into the absorbent material enclosure. ### Claim 13 (depends on 12) The device of claim 12, wherein the precise volume of biological fluid contained by the metering groove is from about 1 μL to about 10 μL. ### Claim 14 A biological fluid dilution device, comprising: a syringe base portion comprising a piston tube at a rear end of the syringe base portion; a syringe end cap pressure fitted to a front end of the syringe base portion to form a diluent chamber, wherein the diluent chamber is partially filled with a diluent fluid; a moveable piston slidably engaged in the piston tube and forming a fluid-tight seal with an interior surface of the piston tube, wherein the moveable piston comprises a metering groove to contain a precise volume of a biological fluid between the metering groove and the interior surface of the piston tube; and a biological fluid inlet on the piston tube capable of delivering the biological fluid to the metering groove, wherein the moveable piston is slidable toward the diluent chamber to introduce the biological fluid in the metering groove into the diluent chamber, and wherein the syringe base portion and syringe end cap are formed of a polymer having a water vapor transmission rate of 0.5 g·mil/(24 hr·100 in2) or less. ### Claim 15 (depends on 14) The device of claim 14, further comprising a vent port aligned with the biological fluid inlet to vent air from the metering groove, wherein the vent port comprises a capillary break to retain excess biological fluid in the vent port, the capillary break including a tapered portion and a narrowed opening with a smaller width than a width of the vent port.