Method for measuring pressures deriving from leakage current

• US 20060217633A1
• Filed: 04/08/2003
• Published: 09/28/2006
• Est. Priority Date: 04/08/2003
• Status: Abandoned Application

• Current Assignee: Pp-Technologies AG
• Original Assignee: Pp-Technologies AG
• Inventors: Ozdemir, Haldun, Glocker, Raymond
• Application Number:
  US10/552,074
• Publication Number:
  US 20060217633A1
• Time in Patent Office: Days
• US Class Current: 600/561
• CPC Class Codes: A61B 5/0048 Detecting, measuring or recording by applying mechanical forces or stimuli A61B5/021, A61B5/4884 and A61B9/00 take precedence
• CPC Class Codes: A61B 5/0215 by means inserted into the body catheters A61M25/00
• CPC Class Codes: A61B 5/036 by means introduced into body tracts A61B5/032 and A61B5/035 take precedence
• CPC Class Codes: A61B 5/037 Measuring oesophageal pressure
• CPC Class Codes: A61B 5/05 Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves impedance plethysmography A61B5/0295; measuring movement of the entire body or parts thereof A61B5/11; detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof A61B5/24
• CPC Class Codes: A61B 5/205 Determining bladder or urethral pressure
• CPC Class Codes: G01L 9/18 by making use of electrokinetic cells, i.e. liquid-containing cells wherein an electric potential is produced or varied upon the application of stress

Abstract

A method for performing pressure measurements by means of pressure profile sensors technique comprises the following steps: a) introducing into the mammal a catheter having at least a portion of its wall which is sufficiently flexible to be deflected by external pressure; b) introducing progressively into the catheter lumen an electrically conductive liquid substance while applying to it simultaneously an alternative current and mechanical oscillations; c) detecting by means of an electrode placed at the external surface of the subject the leakage current induced by the liquid substance traveling in the catheter; d) transferring the leakage current thus recorded to a converter suitable to convert the leakage parameters provided thereto into pressure values; and e) displaying the pressure values as such or as a function of the measurement location or period to afford corresponding pressure profiles. This method is useful for performing pressure, respectively pressure profiles measurements in various mammal body tracts or cavities. The invention also relates to a device using said method.

Claims

1. A method for performing pressure, respectively pressure profile, measurements in mammals by means of the pressure profile sensors technique, which comprises

a) introducing into the mammal a catheter having at least a portion of its wall which is sufficiently flexible to be deflected by external pressure;

b) introducing progressively into the catheter lumen an electrically conductive liquid substance while applying simultaneously to it alternative current and mechanical oscillations;

c) detecting by means of an electrode placed at the external surface of the subject the leakage current induced by the liquid substance traveling through the catheter;

d) transferring the leakage current thus recorded to a converter suitable to convert the leakage current parameters provided thereto into corresponding pressure values; and

e) displaying the pressure values as such, or as a function of the measurement location or measurement period or both to afford corresponding pressure profiles.

2. Method of claim 1, wherein the alternative current is a low voltage/high frequency current and wherein the mechanical oscillations have controlled amplitude and frequency.

3. Method according to claim 1, wherein the catheter is made of innocuous polymer plastic material, preferably of non-conductive innocuous polymer plastic material.

4. Method according to claim 1, wherein the catheter is a single lumen or a multi-lumen catheter.

5. Method according to claim 1, wherein the electrically conductive liquid substance is an aqueous liquid, preferably a saline solution.

6. Method according to claim 1, wherein the liquid substance is progressing step-by-step through the catheter lumen.

7. Method according claims 1, wherein the alternative current voltage applied to the liquid substance is comprised between about 500 mV and about 6 V, preferably between about 1 and about 4 V.

8. Method according to claim 1, wherein the alternative current frequency applied to the liquid substance is comprised between about 60 and 130 kHz, preferably between about 80 and 120 kHz.

9. Method according to claim 1, wherein the mechanical oscillations applied to the liquid substance have an amplitude of about max. 4 mm and a frequency of about max 15 Hz, preferably of about 2 mm, respectively about 10 Hz.

10. Use of the method according to claim 1 for performing pressure, respectively pressure profile measurements in mammal body tracts or cavities such as lung, esophagus, stomach, intestine, urinary tract or bladder, or blood vessels.

11. Use of the method according to claim 1 for performing real time pressure, respectively pressure profile measurements.

12. Use of the method of claim 1 for performing ex-temporaneum pressure, respectively pressure profiles measurements by recording the pressure values provided by the converter and by displaying them at a time different from that of the leakage current recording.

13. An apparatus for performing the method of claim 1, which comprises

a source of an electrically conductive liquid substance connected to an alternative current source;

peristaltic pumping means fitted directly to the source of liquid substance;

mechanical oscillation means connected downwards to peristaltic pumping means;

an electrode placed at the external surface of the subject for recording and then transferring the detected leakage current to the converter;

a converter suitable for deriving pressure values from the leakage current parameters which have been transferred thereto; and

means suitable to display pressure values as such, or as a function of the measurement location or measurement period or both.