Electrical safety methods, devices, and systems for medical treatment devices

Patent metadata

Field	Value
Publication number	US-9636454-B2
Application number	US-201214123066-A
Country	US
Kind code	B2
Filing date	Jun 8, 2012
Priority date	Jun 8, 2011
Publication date	May 2, 2017
Grant date	May 2, 2017

Abstract

Systems, methods, and devices can detect a dangerous or adverse condition or anticipated condition that indicates an undesirable amount of electric current in a patient-connected tube providing fluid to a patient. The fluid flow to the patient is stopped responsive to the detection. Stoppage of fluid flow to the patient can reduce or prevent electric current in the fluid from reaching a patient, flowing through the patient to ground, and/or continuing to flow through the patient.

First claim

What is claimed is:

1. A method for protecting a patient from an electrical source, comprising:
connecting the patient to a treatment device by a fluid line;
receiving a voltage or current signal indicating a flow of current or voltage in the fluid line connected to the patient from a sensor configured to electrically couple to a fluid in the line to detect current or voltage in the fluid at a position in the fluid line proximate to the sensor;
determining if the voltage or current exceeds a predetermined threshold; and
in response to the determining, breaking fluid continuity between the patient and the treatment device to halt the flow of current in the fluid carried by the fluid line.

2. The method of claim 1 , further comprising generating a human perceptible output indicating the excessive detected voltage or current.

3. A system for protecting a patient from an electrical source, the system comprising:
a fluid line connected to the patient;
a sensor configured to electrically couple to a fluid in the fluid line and output a voltage signal or a current signal indicating a flow of current or a voltage in the fluid at a position in the fluid line proximate to the sensor;
means for determining if the voltage or the current exceeds a predetermined threshold; and
means for closing a valve to break continuity between the patient and the treatment device and halt the flow of current in the fluid carried by the fluid line in response to the determined voltage or current.

4. The system of claim 3 , further comprising means for generating a human perceptible output indicating the excessive detected voltage or current.

5. A system for stopping flow of a conductive fluid to a patient, comprising:
a sensor configured to be electrically coupled to the conductive fluid in a fluid line identifying an unsatisfactory condition in the system indicative of patient leakage current or anticipated patient leakage current of an unacceptable amount; and
means for stopping fluid continuity of the conductive fluid in the fluid line from a treatment machine to the patient and halting the flow of current in the fluid line based on the identified unsatisfactory condition.

6. The system according to claim 5 , wherein said means for stopping the fluid flow continuity to the patient mechanically interrupts the fluid conductive path to the patient.

7. The system according to claim 5 , wherein said means for stopping the fluid flow continuity to the patient includes a pinching apparatus that pinches closed a corresponding fluid flow line.

8. The system according to claim 5 , wherein said means for stopping the fluid flow continuity to the patient includes a valve to divert flow to a circuit having an air break.

9. The system according to claim 8 , wherein the circuit has a drip chamber.

10. The system according to claim 5 , wherein the unsatisfactory condition is one or more of a sensed patient leakage current exceeding a predetermined amount, a sensed voltage differential associated with the patient leakage current exceeding a predetermined amount, a fault condition, an anticipated fault condition, a sensed change in fluid conductivity, a disconnection from ground, and vibration.

11. The system according to claim 5 , wherein the fluid continuity is temporarily interrupted without shutting down a means for supplying conductive fluid to the patient, wherein, once the unsatisfactory condition is resolved, the fluid continuity to the patient is restored.

12. The system according to claim 5 , wherein the acceptable amount of patient leakage current is zero.

13. The system according to claim 5 , wherein the acceptable amount of patient leakage current is 10 μA or below 10 μA.

14. The system according to claim 5 , wherein said means for stopping fluid continuity to the patient causes reduction of patient leakage current to keep within or reduce to an acceptable limit.

15. The system according to claim 5 , wherein unsatisfactory condition is a fault condition.

16. The system according to claim 5 , wherein the system is operative to stop fluid continuity to the patient when a fluid treatment machine thereof sinks to earth patient leakage current caused by external voltage applied to the patient.

17. The system according to claim 5 , further comprising means for handling fluid coupled to the patient via one or more patient fluid flow lines, wherein normal operation of said fluid handling means is interrupted responsively to the unsatisfactory condition indication.

18. The system according to claim 5 , wherein the unsatisfactory condition indication is predictive of a harmful, dangerous, or adverse situation to the patient.

19. The system according to claim 5 , wherein said means for stopping fluid continuity to the patient includes redundant devices of same or different types for stopping fluid continuity.

20. The system according to claim 5 , wherein stopping fluid continuity to the patient prevents or stops electric shock to the patient.

21. The system according to claim 5 , wherein said means for identifying an unsatisfactory condition in the system includes
one or more of at least one sensor disposed external to means for handling fluid and operative to sense a characteristic of a fluid line providing the conductive fluid to the patient;
at least one sensor disposed internal to said means for handling fluid and operative to sense a characteristic of said means for handling fluid indicative of patient leakage current or an anticipated occurrence of patient leakage current; and at least one sensor disposed on or in association with the patient to sense indications of patient leakage current or an anticipated occurrence of patient leakage current.

22. The system according to claim 5 , wherein said means for stopping the fluid flow continuity to the patient includes a valve to break continuity between the patient and a treatment device.

23. The system according to claim 5 , wherein said means for stopping the fluid flow continuity to the patient includes a folding apparatus to fold the tube to close the corresponding fluid flow line.

24. The system according to claim 5 , wherein said means for stopping the fluid flow continuity to the patient includes a bubble introducing apparatus to introduce air into the fluid flow line to form an air break.

25. The system according to claim 5 , wherein said sensor is a capacitive sensor.

Assignees

• Kogan Yakov
• Nxstage Medical Inc

Inventors

• Kogan Yakov

Classifications

• A61M1/14 Primary

  Dialysis systems; Artificial kidneys; Blood oxygenators (semi-permeable membranes characterised by the material, manufacturing processes therefor B01D71/00){; Reciprocating systems for treatment of body fluids, e.g. single needle systems for hemofiltration or pheresis} · CPC title

• A61M1/3496

  Plasmapheresis; Leucopheresis; Lymphopheresis (A61M1/3472 takes precedence) · CPC title

• A61M1/38

  Removing constituents from donor blood and {storing or} returning remainder to body {, e.g. for transfusion} · CPC title

• A61M5/44

  having means for cooling or heating the devices or media · CPC title

• A61M5/16831 Primary

  Monitoring, detecting, signalling or eliminating infusion flow anomalies (low-level float-valves causing cut-off A61M5/40; indicating or recording presence, absence or direction of flow in general G01P13/0066) · CPC title