METHOD AND DEVICE FOR TESTING SENSORSTO BE APPLIED ON A PATIENT'S SKIN FORTHE DETECTION OF FLUID OR MOISTURE

• US 20140059837A1
• Filed: 08/28/2013
• Published: 03/06/2014
• Est. Priority Date: 08/31/2012
• Status: Active Grant

• Current Assignee: Fresenius Medical Care Deutschland GmbH (Fresenius Medical Care AG)
• Original Assignee: Fresenius Medical Care Deutschland GmbH (Fresenius Medical Care AG)
• Inventors: Schroers, Alexander, Heppe, John, Rullof, Roland
• Granted Patent: US 9,645,218 B2
• Time in Patent Office: Days
• US Class Current: 29/593
• CPC Class Codes: A61B 2562/029 Humidity sensors
• CPC Class Codes: A61B 2562/12 Manufacturing methods specially adapted for producing sensors for in-vivo measurements
• CPC Class Codes: A61B 5/02042 Determining blood loss or bleeding, e.g. during a surgical procedure
• CPC Class Codes: A61B 5/1495 Calibrating or testing of in-vivo probes
• CPC Class Codes: A61B 5/443 Evaluating skin constituents, e.g. elastin, melanin, water
• CPC Class Codes: A61B 5/6831 Straps, bands or harnesses
• CPC Class Codes: A61F 13/42 with wetness indicator or alarm
• CPC Class Codes: A61F 2013/00429 for conducting tests
• CPC Class Codes: A61M 1/3653 Interfaces between patient blood circulation and extra-corporal blood circuit
• CPC Class Codes: A61M 1/3656 Monitoring patency or flow at connection sites; Detecting disconnections
• CPC Class Codes: A61M 1/3659 Cannulae pertaining to extracorporeal circulation
• CPC Class Codes: A61M 2209/02 Equipment for testing the apparatus
• CPC Class Codes: G01M 3/16 using electric detection means G01M3/045, G01M3/06, G01M3/12, G01M3/20, G01M3/24, G01M3/26 take precedence
• CPC Class Codes: G01R 3/00 Apparatus or processes specially adapted for the manufacture or maintenance of measuring instruments , e.g. of probe tips
• CPC Class Codes: G01R 35/00 Testing or calibrating of apparatus covered by the other groups of this subclass
• CPC Class Codes: Y10T 29/49004 including measuring or testing of device or component part

Abstract

A method and device for testing sensors to be applied on a patient'"'"'s skin for detection of liquid or moisture are described, in particular for monitoring vascular access in an extracorporeal blood treatment, in which a patient'"'"'s blood is carried away from the patient via an arterial line and is fed to the patient via a venous line. A method for producing sensors to be applied on a patient'"'"'s skin for detection of liquid or moisture is also described. The method and device according to the present invention are based on the testing of one or more moisture sensors which are taken from current production. The method includes providing a large number of twists of the moisture sensor applied onto a torsion body, the mechanical stresses thus recreating the stresses that can occur in practice when the moisture sensor is applied or stuck onto the patient'"'"'s skin or forearm.

Claims

1. A method for testing sensors to be applied on a patient'"'"'s skin for detection of liquid or moisture, the sensors comprising an electrically conductive structure with electrical terminals, wherein electrical properties of the sensors are measured under defined conditions and compared with electrical properties preset as a reference value, the method comprising:

removing at least one sensor from production,

applying the at least one sensor onto a surface of an elastic body,

repeatedly deforming the elastic body, and

after the repeated deformation of the elastic body, comparing the measured electrical properties with the preset electrical properties,

determining that the at least one sensor is faulty based on deviations between the measured electrical properties and the preset electrical properties of the at least one sensor.

2. The method according to claim 1, wherein the elastic body is an elastic torsion body, and the repeatedly deforming includes repeatedly twisting.

3. The method according to claim 2, wherein the torsion body is clamped fixedly at one end and is twisted through a preset angle of rotation at another end.

4. The method according to claim 2, wherein the torsion body is a cylindrical body, on a lateral surface whereof the at least one sensor is applied.

5. The method according to claim 2, wherein the torsion body is a hose.

6. The method according to claim 1, wherein a plurality of sensors is removed from a batch of the production, and the deviations between the measured electrical properties and the preset electrical properties of the plurality of sensors removed from the batch are evaluated statistically.

7. The method according to claim 2, wherein the torsion body is twisted through a torsion angle of between 60°

to 180°

, between 80°

to 160°

, or between 100°

to 140°

.

8. The method according to claim 2, wherein a number of twists is between 100 and 1000, between 200 to 800, or between 400 to 600 twists.

9. A method for producing sensors to be applied on a patient'"'"'s skin for detection of moisture, the sensors comprising an electrically conductive structure with electrical terminals, the method comprising:

producing a plurality of sensors disposed beside one another on a common web,

separating the plurality of sensors into single units, and

performing testing on the sensors according to the method of claim 1.

10. The method according to claim 9, wherein the sensors are resistive moisture sensors that measure electrical resistance or a magnitude correlating with the electrical resistance.

11. The method according to claim 9, wherein the sensors are configured as a textile planar structure comprising non-conductive warp threads and non-conductive weft threads and conductive warp threads and conductive weft threads, wherein the non-conductive warp threads and weft threads and the conductive warp threads and weft threads are disposed such that the electrically conductive structure is formed.

12. The method according to claim 9, wherein the sensors comprise a carrier material, onto which the electrically conductive structure is applied or printed.

13. A device for performing testing of sensors according to the method of claim 1, the device for performing testing comprising:

an elastic torsion body to which at least one sensor is applicable,

an operating unit for interchangeable accommodation of the torsion body, and adapted for twisting the torsion body,

a control unit for controlling the operating unit,

a measuring unit for measuring electrical properties of the at least one sensor, and

an evaluation unit for evaluating the measured electrical properties of the at least one sensor.

14. The device according to claim 13, wherein the torsion body is a hose.

15. The device according to claim 14, wherein the operating unit comprises a rotatable cylindrical body to which one end of the hose is attached, and a fixed cylindrical body to which another end of the hose is attached.

16. The device according to claim 13, wherein the control unit is adapted to control the operating unit to perform a preset number of twists of the torsion body.

17. The device according to claim 13, wherein the control unit is adapted to control the operating unit to perform twists through a preset torsion angle.