US4475556A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rapid measurement of colloid osmotic equilibrium pressure
Assignee: Individual
•
Filing: 1983-01-03
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Granted: 1984-10-09
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Expires: 2003-01-03
Abstract
Abstract Rapid colloidal osmometer 10 for readout of osmotic equilibrium pressure comprising a cap of rigid semipermeable ceramic 12, a solvent chamber 14 and a pressure transducer 18. The osmometer is for insertion into a living subject. Osmotic equilibrium pressure is calculated by a data reduction computer 40 and displayed on a chart recorder 42. The computer can also be used to control fluid infusion through a valve 44 into a patient 29. An alternate embodiment comprises an osmometer for high pressure use in a pressure chamber 54 in which the osmometer 56 is braced 58. A solution chamber 57, semipermeable membrane 32, and solvent 55 are held at a high pressure by compressor 78. Osmotic equilibrium is predicted by a computer 40 and displayed on a chart recorder 42.
Inventors
- 👤 Theodore R. Reiff
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:29
CPC Classifications
G; G01; G01N; G01N13/00; G01N13/04
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
91 words
A colloidal osmometer for rapid read-out of osmotic equilibrium pressure comprising: a. a capsule of about 2 mm or less in cross sectional dimension suitable for in vivo insertion; b. a cap of rigid ceramic which forms a semipermeable membrane at an end of the capsule; c. a solvent chamber fully enclosed in the capsule covered at least in part by the cap of rigid ceramic; and d. a pressure transducer in the capsule adjacent to the solvent chamber providing an electrical output indicative of the pressure in the solvent chamber.
Claim 2
Dependent Claim
91 words
A colloidal osmometer for rapid read-out of osmotic equilibrium pressure comprising: a. a capsule of about 2 mm or less in cross sectional dimension suitable for in vivo insertion; b. a cap of rigid ceramic which forms a semipermeable membrane at an end of the capsule; c. a solvent chamber fully enclosed in the capsule covered at least in part by the cap of rigid ceramic; and d. a pressure transducer in the capsule adjacent to the solvent chamber providing an electrical output indicative of the pressure in the solvent chamber.
Claim 3
Dependent Claim
29 words
The colloidal osmometer recited in claim 1 wherein a second pressure transducer in the capsule is used for measurement of ambient pressure in the vicinity of the semipermeable membrane.
Claim 4
Dependent Claim
22 words
The colloidal osmometer recited in claim 1 wherein the capsule is generally cylindrical and the capsule diameter is smaller than 2 mm.
Claim 5
Dependent Claim
16 words
The colloidal osmometer recited in claim 1 wherein the solvent chamber is filled with degassed solvent.
Claim 6
Dependent Claim
98 words
A colloidal osmometer that gives rapid read-out of osmotic equilibrium pressure comprising: a. a pen-like capsule; b. a cap of rigid ceramic which forms a semipermeable pressure dome; c. a solvent chamber covered at least in part by the cap of rigid ceramic; d. a pressure transducer adjacent to the solvent chamber providing a pressure output; and e. electronic computing means for calculating the pressure rate of change across the semipermeable membrane and projecting the osmotic equilibrium pressure from said pressure output; f. an electrical recording device used to record predicted equilibrium data from said electronic computing means.
Claim 7
Dependent Claim
98 words
A colloidal osmometer that gives rapid read-out of osmotic equilibrium pressure comprising: a. a pen-like capsule; b. a cap of rigid ceramic which forms a semipermeable pressure dome; c. a solvent chamber covered at least in part by the cap of rigid ceramic; d. a pressure transducer adjacent to the solvent chamber providing a pressure output; and e. electronic computing means for calculating the pressure rate of change across the semipermeable membrane and projecting the osmotic equilibrium pressure from said pressure output; f. an electrical recording device used to record predicted equilibrium data from said electronic computing means.
Claim 8
Dependent Claim
40 words
A colloidal osmometer as claimed in claim 5 wherein the recording device is a chart recorder with at least one pen capable of recording both the input data from the osmometer and the calculated data from said electronic computing means.
Claim 9
Dependent Claim
129 words
An osmometer for rapid determination of osmotic equilibrium pressure of a solution of solute in solvent comprising: a. a solvent chamber; b. a pressure sensor providing an output proportional to a change in pressure within the solvent chamber caused by passage of fluid across a semipermeable membrane bounding the solvent chamber; c. electronic computing means for calculating the solution's osmotic equilibrium pressure from the pressure sensor output over a period of time shorter than that required for osmotic equilibrium to actually occur by generating a mathematical solution for osmotic equilibrium pressure, as defined as ##EQU2## wherein: P eq is osmotic equilibrium pressure, t is real time, P o is initial pressure, t o is initial time and, P is pressure measured by the pressure transducer at a finite time.
Claim 10
Dependent Claim
129 words
An osmometer for rapid determination of osmotic equilibrium pressure of a solution of solute in solvent comprising: a. a solvent chamber; b. a pressure sensor providing an output proportional to a change in pressure within the solvent chamber caused by passage of fluid across a semipermeable membrane bounding the solvent chamber; c. electronic computing means for calculating the solution's osmotic equilibrium pressure from the pressure sensor output over a period of time shorter than that required for osmotic equilibrium to actually occur by generating a mathematical solution for osmotic equilibrium pressure, as defined as ##EQU2## wherein: P eq is osmotic equilibrium pressure, t is real time, P o is initial pressure, t o is initial time and, P is pressure measured by the pressure transducer at a finite time.
Claim 11
Independent Claim
130 words
A method of determining the in vivo colloid osmotic pressure of living subjects comprising the steps of: a. inserting into a subject a capsule with a solvent chamber bordered by a semipermeable pressure dome; b. measuring any change in pressure in the solvent chamber with a pressure transducer; c. measuring the ambient pressure of the fluid in which the probe is immersed; d. transmitting a pressure signal from a pressure transducer at the solvent chamber to an input for a computing device; e. computing the rate of change of the pressure within the solvent chamber as changed by passage of fluid across the semipermeable membrane; f. predicting a theoretical osmotic equilibrium pressure based on said rate of change; and, g. recording the theoretical osmotic equilibrium pressure on a recording device.
Claim 12
Independent Claim
130 words
A method of determining the in vivo colloid osmotic pressure of living subjects comprising the steps of: a. inserting into a subject a capsule with a solvent chamber bordered by a semipermeable pressure dome; b. measuring any change in pressure in the solvent chamber with a pressure transducer; c. measuring the ambient pressure of the fluid in which the probe is immersed; d. transmitting a pressure signal from a pressure transducer at the solvent chamber to an input for a computing device; e. computing the rate of change of the pressure within the solvent chamber as changed by passage of fluid across the semipermeable membrane; f. predicting a theoretical osmotic equilibrium pressure based on said rate of change; and, g. recording the theoretical osmotic equilibrium pressure on a recording device.
Claim 13
Independent Claim
153 words
A method of controlling intravascular colloid osmotic pressure of a system comprising the steps of: a. inserting into the system a probe with a solvent chamber bordered by a semipermeable pressure dome; b. measuring any change in pressure in the solvent chamber with a pressure transducer; c. measuring the ambient pressure of the fluid in which the osmometer is immersed; d. transmitting a pressure signal from the pressure transducer at the solvent chamber to an input for a computing device; e. computing the rate of change of the osmotic pressure within the solvent chamber as changed by passage of fluid across the semipermeable membrane; f. predicting a theoretical osmotic equilibrium pressure based on said rate of change; g. recording both the data from the first pressure transducer and the calculated prediction on a recording device; and, h. controlling at least one valve to meter the rate of fluid solution infusion to the system.
Claim 14
Independent Claim
153 words
A method of controlling intravascular colloid osmotic pressure of a system comprising the steps of: a. inserting into the system a probe with a solvent chamber bordered by a semipermeable pressure dome; b. measuring any change in pressure in the solvent chamber with a pressure transducer; c. measuring the ambient pressure of the fluid in which the osmometer is immersed; d. transmitting a pressure signal from the pressure transducer at the solvent chamber to an input for a computing device; e. computing the rate of change of the osmotic pressure within the solvent chamber as changed by passage of fluid across the semipermeable membrane; f. predicting a theoretical osmotic equilibrium pressure based on said rate of change; g. recording both the data from the first pressure transducer and the calculated prediction on a recording device; and, h. controlling at least one valve to meter the rate of fluid solution infusion to the system.
Claim 15
Independent Claim
155 words
A method of determining the osmotic pressure of solutions of substances in high pressure environments comprising the steps of: a. inserting into a pressure chamber an osmometer with a solvent chamber, a semipermeable membrane and, a solution whose osmotic pressure is to be measured; b. controlling environmental pressure in the chamber in which the osmometer and sample are positioned; c. recording the change in pressure in the osmometer solvent chamber; d. transmitting a signal from a pressure transducer in the osmometer to an input for a computing device; e. computing a time rate of change of the osmotic pressure within the solvent chamber as changed by the passage of fluid across the semipermeable membrane; f. predicting a theoretical final osmotic equilibrium pressure based on the time rate of change of pressure within solvent chamber of osmotic pressure; and, g. recording both actual osmometer pressure and the calculated osmotic equilibrium prediction on an electrical recording device.
Claim 16
Independent Claim
155 words
A method of determining the osmotic pressure of solutions of substances in high pressure environments comprising the steps of: a. inserting into a pressure chamber an osmometer with a solvent chamber, a semipermeable membrane and, a solution whose osmotic pressure is to be measured; b. controlling environmental pressure in the chamber in which the osmometer and sample are positioned; c. recording the change in pressure in the osmometer solvent chamber; d. transmitting a signal from a pressure transducer in the osmometer to an input for a computing device; e. computing a time rate of change of the osmotic pressure within the solvent chamber as changed by the passage of fluid across the semipermeable membrane; f. predicting a theoretical final osmotic equilibrium pressure based on the time rate of change of pressure within solvent chamber of osmotic pressure; and, g. recording both actual osmometer pressure and the calculated osmotic equilibrium prediction on an electrical recording device.
Claim 17
Dependent Claim
87 words
A colloidal osmometer for in vivo measurement of osmotic equilibrium pressure comprising a transducer assembly of about 2 mm or less in cross sectional dimension suitable for in vivo insertion, the transducer assembly having a solvent chamber fully enclosed therein near the tip thereof closed by a semipermeable membrane which forms a part of an outer wall of the transducer assembly and a pressure transducer in the transducer assembly adjacent to the solvent chamber for providing an electrical output indicative of the pressure in the solvent chamber.
Claim 18
Dependent Claim
87 words
A colloidal osmometer for in vivo measurement of osmotic equilibrium pressure comprising a transducer assembly of about 2 mm or less in cross sectional dimension suitable for in vivo insertion, the transducer assembly having a solvent chamber fully enclosed therein near the tip thereof closed by a semipermeable membrane which forms a part of an outer wall of the transducer assembly and a pressure transducer in the transducer assembly adjacent to the solvent chamber for providing an electrical output indicative of the pressure in the solvent chamber.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-10-09 | 1988-04-09 | 1988-10-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-10-09 | 1992-04-09 | 1992-10-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-10-09 | 1996-04-09 | 1996-10-09 | $7700.00 | Window Closed / Lapsed |