Abstract:
A sorbent hemodialysis system includes a dialyzer configured to receive a flow of clean dialysate from a reservoir and to output an unclean dialysate flow. The system also includes a sorbent component having a urease section and a sorbent section through which the unclean dialysate flow from the dialyzer passes, wherein the sorbent component removes urea from the dialysate. The system further comprises a membrane electrolyzer that receives at least a portion of said clean dialysate flow and separates the dialysate flow into an acidic component flow and a base component flow. A mixing conduit combines the base component flow from the membrane electrolyzer and an output dialysate solution from the urease section of the sorbent component to separate the dialysate solution into an ammonia gas amount and ammonia liquid amount. A gas vent is used to vent the ammonia gas amount, and the sorbent section with a suitable amount of zirconium phosphate (ZrP) removes the ammonia liquid amount from the unclean dialysate flow before flowing the clean dialysate to the reservoir. The system can further include a second mixing conduit upstream of the sorbent section of the sorbent component, the second mixing conduit combining the acidic component flow and the ammonia liquid amount in the dialysate solution to increase the pH of the dialysate solution to about 7.5 prior to returning to the reservoir.
Abstract:
In certain embodiments, a method samples a body fluid of a patient. The method includes providing a fluid handling system having one or more fluid passageways. The method further includes infusing an infusion fluid by way of a fluid handling system into a patient through one or more fluid passageways. The method further includes obtaining a sample of body fluid by way of a fluid handling system from a patient through one or more fluid passageways. The obtained sample is no more than 5 milliliters in volume. The method further includes analyzing at least an analyzed portion of the obtained sample by way of an analyte detection system operatively associated with the fluid handling system to determine a concentration of at least one analyte.
Abstract:
An apparatus is provided for monitoring a predetermined parameter of a patient's body fluid while infusing an infusion fluid into the patient. The apparatus comprises an infusion line and a catheter configured for insertion into a blood vessel of the patient, and a reversible infusion pump connected between a source of an infusion fluid and the infusion line and catheter. The apparatus further comprises a body fluid sensor assembly mounted in fluid communication with the infusion line and which includes a first sensor and a sample cell. The first sensor provides a signal indicative of a predetermined parameter of any fluid present in the infusion line. The sample cell is substantially transmissive to light comprising a wavelength λ. The apparatus further comprises a controller that is configured to operate the infusion pump in a forward direction so as to pump the infusion fluid through the infusion line and catheter for infusion into the patient. The controller is configured to intermittently interrupt its operating of the infusion pump in the forward direction to operate the infusion pump in a rearward direction so as to draw a body fluid sample from the patient through the catheter and infusion line. The body fluid sample drawn from the patient is disposed such that a first portion of the body fluid sample is in sensing contact with the first sensor of the body fluid sensor assembly, and a second portion of the body fluid sample is disposed within the sample cell of the body fluid sensor assembly. The controller further is configured to monitor the signal provided by the first sensor of the body fluid sensor assembly and to detect a change in the signal indicative of the arrival of the body fluid sample at the first sensor. The controller, in response to detecting the arrival of the body fluid sample at the first sensor, is configured to cease its operating of the infusion pump in the rearward direction. The signal produced by the first sensor provides an indication of a predetermined parameter of the patient's body fluid when the body fluid sample is in sensing contact with the first sensor.
Abstract:
A fluid handling module is configured for removable engagement with a reusable main fluid handling instrument. The module comprises a housing, an infusion fluid passageway, a sample fluid passageway, and a fluid component separator. The infusion fluid passageway has a first port and a second port spaced from the first port, and a lumen extending from the first port to the second port. The sample fluid passageway is connected to the infusion fluid passageway. The fluid component separator is connected to the sample fluid passageway.
Abstract:
An apparatus is provided for monitoring a predetermined parameter of a patient's body fluid while infusing an infusion fluid into the patient. The apparatus comprises an infusion line and a catheter configured for insertion into a blood vessel of the patient, and a reversible infusion pump connected between a source of an infusion fluid and the infusion line and catheter. The apparatus further comprises a body fluid sensor assembly mounted in fluid communication with the infusion line and which includes a first sensor and a sample cell. The first sensor provides a signal indicative of a predetermined parameter of any fluid present in the infusion line. The sample cell is substantially transmissive to light comprising a wavelength B. The apparatus further comprises a controller that is configured to operate the infusion pump in a forward direction so as to pump the infusion fluid through the infusion line and catheter for infusion into the patient. The controller is configured to intermittently interrupt its operating of the infusion pump in the forward direction to operate the infusion pump in a rearward direction so as to draw a body fluid sample from the patient through the catheter and infusion line. The body fluid sample drawn from the patient is disposed such that a first portion of the body fluid sample is in sensing contact with the first sensor of the body fluid sensor assembly, and a second portion of the body fluid sample is disposed within the sample cell of the body fluid sensor assembly. The controller further is configured to monitor the signal provided by the first sensor of the body fluid sensor assembly and to detect a change in the signal indicative of the arrival of the body fluid sample at the first sensor. The controller, in response to detecting the arrival of the body fluid sample at the first sensor, is configured to cease its operating of the infusion pump in the rearward direction. The signal produced by the first sensor provides an indication of a predetermined parameter of the patient's body fluid when the body fluid sample is in sensing contact with the first sensor.
Abstract:
A sample element configured to hold a material sample for determining a concentration of an analyte in the material sample. The sample element comprises a first window, a sample chamber partially defined by the first window, and a second, moveable window substantially aligned with the first window and the sample chamber. The second window is moveable from a first position in which the second window is spaced from the sample chamber, to a second position in which the second window covers and at least partially encloses the sample chamber.
Abstract:
Methods and apparatus are provided for determining the concentration of an analyte in a sample, such as an analyte in a sample of bodily fluid. Some embodiments use a synchronous demodulator and digital filter to reduce microphonic signal content. Some embodiments monitor the microphonic signal content and “hold off” on making a measurement until vibrations subside. Monitoring can be performed using an accelerometer or other vibration sensor. An algorithm can be used to examine the detector output signal and detect excessive microphonic components, making an accelerometer unnecessary.
Abstract:
An apparatus is presented for estimating the concentration of an analyte using a combined enzyme-spectroscopic method. Examples are provided for the detection of glucose and lactate. A sample of biological fluid is mixed or contacted with an enzyme specific to the analyte of interest, and the reacting fluid is probed with an optical system at wavelengths that includes at least one wavelength that is sensitive to the analyte concentration and at least one wavelength that is not sensitive to the analyte concentration. The optical system measures properties, such as optical density, and relates the measurements to concentration through a calibration of the system. A method is also provided for analyzing the data obtained from optical measurements of reactions of enzymes with biological fluids. These technologies may be applied to continuous or periodic patient sampling systems or to test strip type devices.
Abstract:
A method of extracting and analyzing bodily fluids from a patient at the point of care for the patient is provided. The method comprises establishing fluid communication between an analyte detection system and a bodily fluid in the patient. A portion of the bodily fluid is drawn from the patient. The drawn portion is separated into a first component of the bodily fluid, while the analyte detection system remains in fluid communication with the patient. The analyte detection system analyzes the first component to measure a concentration of an analyte.
Abstract:
An apparatus for analyzing the composition of bodily fluid. The apparatus comprises a fluid handling network including a patient end configured to maintain fluid communication with a bodily fluid in a patient; and a pump unit in operative engagement with the fluid handling network. The pump unit has an infusion mode in which the pump unit is operable to deliver infusion fluid to the patient through the patient end, and a sample draw mode in which the pump unit is operable to draw a sample of the bodily fluid from the patient through the patient end. The apparatus further comprises a spectroscopic analyzer positioned to analyze at least a portion of the sample; a processor in communication with or incorporated into the spectroscopic analyzer; and stored program instructions executable by the processor to obtain measurements of two or more properties of the sample. In one implementation, the pump unit comprises a first pump operable in the infusion mode but not in the sample draw mode, and a second pump operable in the sample draw mode but not in the infusion mode.