Medical treatment system and method

Abstract

A treatment system and method for treating a fluid withdrawn and then returned to a living body. The system includes outgoing and incoming fluid lines connected to the living body for transporting the fluid from the living body, through the treatment system, and back to the living body, a device for altering at least the density of the fluid as it flows through the system, and a sensing unit within the system and comprising a device for sensing the density of the fluid as the fluid flows through the sensing unit. The sensing device may be a micromachined Coriolis-based sensor also capable of sensing mass flow rate.

1 . A treatment system in which a fluid is withdrawn and then returned to a living body, the system comprising: 
 outgoing and incoming fluid lines connected to the living body for transporting the fluid from the living body, through the treatment system, and back to the living body;    means for altering at least the density of the fluid as it flows through the system; and    a sensing unit within the system and comprising means for sensing at least the density of the fluid as the fluid flows through the sensing unit.    
     
     
         2 . The treatment system according to  claim 1 , wherein the treatment system performs a treatment chosen from the group consisting of hemodialysis, peritoneal dialysis, hemofiltration, and assistance to kidneys, lungs, liver, and artificial organs of the living body.  
     
     
         3 . The treatment system according to  claim 1 , wherein the sensing means further comprises means for sensing the temperature of the fluid.  
     
     
         4 . The treatment system according to  claim 1 , wherein the altering means comprises means for introducing an ingredient into the fluid as the fluid flows through the system.  
     
     
         5 . The treatment system according to  claim 1 , wherein the altering means comprises means for removing an ingredient of the fluid as the fluid flows through the system.  
     
     
         6 . The treatment system according to  claim 1 , wherein the sensing unit further comprises means for communicating a density output to a remote unit.  
     
     
         7 . The treatment system according to  claim 1 , wherein the sensing unit further comprises means for sensing at least one of the flow direction and the flow rate of the fluid as the fluid flows through the sensing unit.  
     
     
         8 . The treatment system according to  claim 1 , wherein the sensing unit comprises: 
 a tube comprising a freestanding tube portion through which the fluid flows;    means for vibrating the freestanding tube portion of the tube at a resonant frequency thereof that varies with the density of the fluid flowing therethrough, the Coriolis effect causing the freestanding tube portion to twist while being vibrated at resonance, the freestanding tube portion exhibiting a degree of twist that varies with the mass flow rate of the fluid flowing therethrough; and    means for sensing movement of the freestanding tube portion of the tube, the movement-sensing means producing a first output signal based on the resonant frequency of the freestanding tube portion and a second output signal based on the degree of twist of the freestanding tube portion.    
     
     
         9 . The treatment system according to  claim 1 , wherein the treatment system performs hemodialysis and the fluid is blood.  
     
     
         10 . The treatment system according to  claim 9 , wherein the sensing unit senses the concentration of a component of the blood chosen from the group consisting of urea, hematocrit, blood cells, water, and anticoagulant.  
     
     
         11 . The treatment system according to  claim 9 , further comprising means for controlling the altering means based on the sensed density of the blood.  
     
     
         12 . The treatment system according to  claim 9 , wherein the altering means comprises means for introducing an anticoagulant into the blood, and the sensing unit senses the concentration of the anticoagulant introduced into the blood by the introducing means.  
     
     
         13 . The treatment system according to  claim 12 , further comprising a second sensing unit comprising means for sensing the flow rate of the anticoagulant into the blood.  
     
     
         14 . The treatment system according to  claim 9 , wherein the altering means comprises a dialyzer through which a dialysate solution and the blood flow to perform dialysis on the blood, and the treatment system further comprises a second sensing unit that senses the density and flow rate of the dialysate solution entering the dialyzer.  
     
     
         15 . The treatment system according to  claim 9 , wherein the altering means comprises a dialyzer through which a dialysate solution and the blood flow to perform dialysis on the blood, and the treatment system further comprises a second sensing unit that senses the density of the dialysate solution leaving the dialyzer.  
     
     
         16 . The treatment system according to  claim 15 , further comprising a source of water, a source of dialysate concentrate, means for combining the water and dialysate concentrate to form the dialysate solution, a third sensing unit comprising means for sensing the flow rate of the water to the combining means, and a fourth sensing unit comprising means for sensing the flow rate of the dialysate concentrate to the combining means.  
     
     
         17 . The treatment system according to  claim 9 , wherein the sensing unit is sufficiently sensitive to the density of the blood to detect sterilization fluids in the blood flowing through the treatment system.  
     
     
         18 . The treatment system according to  claim 9 , wherein the sensing unit is sufficiently sensitive to the density of the blood to detect air bubbles in the blood flowing through the treatment system.  
     
     
         19 . The treatment system according to  claim 9 , wherein the sensing unit further comprises means for sensing the flow rate of the blood through the treatment system, the treatment system further comprising means in communication with the sensing unit for detecting leakage of blood from the treatment system based on the flow rate sensed by the sensing unit.  
     
     
         20 . The treatment system according to  claim 1 , further comprising means for receiving a density output from the sensing unit and controlling the altering means based on the density output.  
     
     
         21 . A method of treating a fluid of a living body, the method comprising the steps of: 
 withdrawing the fluid form the living body and into a treatment system;    altering at least the density of the fluid as it flows through the treatment system;    sensing at least the density of the fluid as it flows through the treatment system; and then    returning the fluid to the living body.    
     
     
         22 . The method according to  claim 21 , wherein the method performs a treatment chosen from the group consisting of hemodialysis, peritoneal dialysis, hemofiltration, and assistance to kidneys, lungs, liver, and artificial organs of the living body.  
     
     
         23 . The method according to  claim 21 , further comprising the step of sensing the temperature of the fluid as it flows through the system.  
     
     
         24 . The method according to  claim 21 , wherein the altering step comprises introducing an ingredient into the fluid as the fluid flows through the system.  
     
     
         25 . The method according to  claim 21 , wherein the altering step comprises removing an ingredient of the fluid as the fluid flows through the system.  
     
     
         26 . The method according to  claim 21 , further comprising the step of communicating the density to a remote unit.  
     
     
         27 . The method according to  claim 21 , further comprising the step of sensing at least one of the flow direction and the flow rate of the fluid as the fluid flows through the treatment system.  
     
     
         28 . The method according to  claim 21 , wherein the sensing step is performed with a sensing unit comprising: 
 a tube comprising a freestanding tube portion through which the fluid flows;    means for vibrating the freestanding tube portion of the tube at a resonant frequency thereof that varies with the density of the fluid flowing therethrough, the Coriolis effect causing the freestanding tube portion to twist while being vibrated at resonance, the freestanding tube portion exhibiting a degree of twist that varies with the mass flow rate of the fluid flowing therethrough; and    means for sensing movement of the freestanding tube portion of the tube, the movement-sensing means producing a first output signal based on the resonant frequency of the freestanding tube portion and a second output signal based on the degree of twist of the freestanding tube portion.    
     
     
         29 . The method according to  claim 21 , wherein the method performs hemodialysis on a patient and the fluid is blood of the patient.  
     
     
         30 . The method according to  claim 29 , wherein the sensing step senses the concentration of a component of the blood chosen from the group consisting of urea, hematocrit, blood cells, water, and anticoagulant.  
     
     
         31 . The method according to  claim 29 , further comprising the step of controlling the altering step based on the sensed density of the blood.  
     
     
         32 . The method according to  claim 29 , wherein the altering step comprises introducing an anticoagulant into the blood, and the sensing step senses the concentration of the anticoagulant introduced into the blood.  
     
     
         33 . The method according to  claim 32 , further comprising the step of sensing the flow rate of the anticoagulant into the blood.  
     
     
         34 . The method according to  claim 29 , wherein the altering step comprises a dialyzer through which a dialysate solution and the blood flow to perform dialysis on the blood, and the method further comprises sensing the density and flow rate of the dialysate solution entering the dialyzer.  
     
     
         35 . The method according to  claim 29 , wherein the altering step comprises flowing a dialysate solution and the blood through a dialyzer to perform dialysis on the blood, and the sensing step senses the density of the dialysate solution leaving the dialyzer.  
     
     
         36 . The method according to  claim 35 , further comprising the steps of: 
 combining water and a dialysate concentrate to form the dialysate solution;    sensing the flow rate of the water being combined with the dialysate concentrate; and    sensing the flow rate of the dialysate concentrate combined with the water.    
     
     
         37 . The method according to  claim 29 , wherein the sensing step detects sterilization fluids in the blood.  
     
     
         38 . The method according to  claim 29 , wherein the sensing step detects air bubbles in the blood.  
     
     
         39 . The method according to  claim 29 , further comprising sensing the flow rate of the blood in the system and detecting leakage of blood based on the flow rate.  
     
     
         40 . The method according to  claim 29 , further comprising the step of sensing the density of urine excreted by the patient and then initiating or controlling the method in response to the density of the urine.  
     
     
         41 . The method according to  claim 21 , further comprising the step of controlling the altering step based on the sensed density of the fluid.