Hemodialysis system reservoir level sensor
Inventors
MITROVIC, MIROSLAV • Dandler, Andres • Poppe, Clayton • BOYLE, DYLAN
Assignees
Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
Publication Number
US-11517653-B2
Publication Date
2022-12-06
Expiration Date
Abstract
A portable hemodialysis system is provided including a dialyzer, a closed loop blood flow path which transports blood from a patient to the dialyzer and back to the patient, and a closed loop dialysate flow path which transports dialysate through the dialyzer. In addition, the hemodialysis system includes two reservoirs which can be alternately placed in the dialysis flow path using various controllable fluid valves. The weight, and therefore the level of dialysate, of each reservoir is measured by a preferred level sensor having a lever arm, a load cell, and a tilt sensor. The load cell and tilt sensor are electrically connected to a processor for sending force and tilt measurements to the processor. The processor may analyze the tilt measurements to correct for any inaccurate measurements of the load cell caused by the tilt.
Core Innovation
The invention is a portable hemodialysis system that includes a reservoir level sensor for determining the level of dialysate in a reservoir. The system includes a machine housing, an arterial blood line, a venous blood line, a dialyzer, and a blood flow path transporting blood from the patient to the dialyzer and back to the patient. An isolated dialysate flow path is connected to the reservoir and the dialyzer for transporting dialysate from the reservoir to the dialyzer, with a first pump for pumping dialysate and a second pump for pumping blood, and a filter connected to the dialysate flow path for removing uremic toxins from dialysate.
The reservoir level sensor uses a lever arm pivotally affixed to the machine housing at a pivot point. The lever arm includes a horizontal member that cantilevers horizontally from the pivot point and a vertical member that extends vertically from the pivot point, with the reservoir positioned to hang upon the horizontal member. The weight of the reservoir and dialysate exerts a downward force upon the horizontal member, causing the lever arm to rotate at the pivot point and causing the vertical member to exert a force against a load cell affixed to the machine housing, thereby producing level sensor electrical signals.
A processor connected to the reservoir level sensor's load cell processes the level sensor electrical signals to determine the level of dialysate in the reservoir. In embodiments with two dialysate reservoirs, each reservoir has a respective reservoir level sensor constructed with a lever arm pivotally affixed to the machine housing and a load cell producing electrical signals, and the processor determines the level of dialysate in each reservoir based on the corresponding electrical signals. Safety-related control is refined by adding tilt measurements from a tilt sensor to the processor, and the processor can disable dialysis when tilt is unsafe or incorporate tilt measurements into the dialysate-level determination.
Claims Coverage
The provided material includes two independent claims. Across the independent claims, the coverage focuses on dialysate level determination using lever-arm/load-cell reservoir level sensors, including single-reservoir and two-reservoir configurations, with processing by a processor and embodiments incorporating tilt sensor information and/or disabling conditions.
Hemodialysis system with lever arm and load cell reservoir level sensor
A hemodialysis system comprising a machine housing; arterial blood line for connecting to a patient's artery; venous blood line for connecting to a patient's vein; a dialyzer; a blood flow path connected to said arterial blood line and said venous blood line for transporting blood from a patient to said dialyzer and back to a patient; a reservoir for storing dialysate; a dialysate flow path isolated from the blood flow path connected to said reservoir and said dialyzer for transporting dialysate; a first pump for pumping dialysate through said dialysate flow path; a second pump for pumping blood through said blood flow path; a filter connected to said dialysate flow path for removing uremic toxins from dialysate; a reservoir level sensor which measures the level of dialysate in said reservoir, said level sensor including a lever arm pivotally affixed to said machine housing at a pivot point, said lever arm includes a horizontal member which cantilevers horizontally from said pivot point and a vertical member which extends vertically from said pivot point, said reservoir positioned to hang upon said horizontal member with the weight of said reservoir and dialysate within said reservoir exerting a downward force upon said horizontal member, said level sensor further including a load cell which produces level sensor electrical signals, said load cell affixed to said machine housing and positioned to engage said vertical member such that a downward force exerted by the weight of said reservoir and dialysate upon said lever arm's horizontal member causes said lever arm to rotate at said pivot point and cause said lever arm vertical member to exert a force against said load cell to produce said level sensor electrical signals; and a processor connected to said reservoir level sensor's load cell for processing said level sensor electrical signals to determine the level of dialysate in said reservoir.
Hemodialysis system with first and second reservoir level sensors using lever arm and load cell
A hemodialysis system with reservoir level sensors comprising a machine housing; an arterial blood line for connecting to a patient's artery; a venous blood line for connecting to a patient's vein; a dialyzer; a blood flow path connected to said arterial blood line and said venous blood line for transporting blood from a patient to said dialyzer and back to a patient; a first reservoir for storing dialysate and a second reservoir for storing dialysate; a dialysate flow path isolated from the blood flow path connected to said reservoir and said dialyzer for transporting dialysate; a first pump for pumping dialysate through said dialysate flow path; a second pump for pumping blood through said blood flow path; a filter connected to said dialysate flow path for removing uremic toxins from dialysate; a first reservoir level sensor which measures the level of dialysate in said first reservoir, said level sensor including a lever arm pivotally affixed to said machine housing at a pivot point, said lever arm includes a horizontal member which cantilevers horizontally from said pivot point and a vertical member which extends vertically from said pivot point, said first reservoir positioned to hang upon said horizontal member with the weight of said first reservoir and dialysate within said first reservoir exerting a downward force upon said horizontal member, said level sensor further including a load cell which produces level sensor electrical signals, said load cell affixed to said machine housing and positioned to engage said vertical member such that a downward force exerted by the weight of said first reservoir and dialysate upon said lever arm's horizontal member causes said lever arm to rotate at said pivot point and cause said lever arm vertical member to exert a force against said load cell to produce said level sensor electrical signals; a second reservoir level sensor which measures the level of dialysate in said second reservoir, said level sensor including a lever arm pivotally affixed to said machine housing at a pivot point, said lever arm includes a horizontal member which cantilevers horizontally from said pivot point and a vertical member which extends vertically from said pivot point, said second reservoir positioned to hang upon said horizontal member with the weight of said second reservoir and dialysate within said second reservoir exerting a downward force upon said horizontal member, said level sensor further including a load cell which produces level sensor electrical signals, said load cell affixed to said machine housing and positioned to engage said vertical member such that a downward force exerted by the weight of said second reservoir and dialysate upon said lever arm's horizontal member causes said lever arm to rotate at said pivot point and cause said lever arm vertical member to exert a force against said load cell to produce said level sensor electrical signals; and a processor connected to said first reservoir level sensor's load cell for processing said level sensor electrical signals to determine the level of dialysate in said first reservoir and said processor connected to said second reservoir level sensor's load cell for processing said level sensor electrical signals to determine the level of dialysate in said second reservoir.
Across the independent claims, the central claim coverage is the lever-arm/load-cell reservoir level sensor arrangement for measuring dialysate level and providing electrical signals to a processor. Dependent claims in the provided material further cover operational refinements including disabling the system based on dialysate level thresholds, using a tilt sensor and a processor response based on predetermined inclination or incorporating tilt measurements into dialysate-level determination.
Stated Advantages
Enables determining the level of dialysate in a reservoir by processing level sensor electrical signals.
Enables determining the level of dialysate in first and second reservoirs using corresponding reservoir level sensors.
Enables shutdown/disable of the system when dialysate level is below a predetermined threshold.
Enables shutdown/disable of the system when machine housing tilt exceeds a predetermined inclination or enables incorporating tilt measurements into dialysate-level determination.
Documented Applications
Not explicitly described in patent.
Interested in licensing this patent?