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WO1991012765A1 - Multisondes avec detecteur de flux a diffusion thermique - Google Patents

Multisondes avec detecteur de flux a diffusion thermique Download PDF

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Publication number
WO1991012765A1
WO1991012765A1 PCT/US1991/000322 US9100322W WO9112765A1 WO 1991012765 A1 WO1991012765 A1 WO 1991012765A1 US 9100322 W US9100322 W US 9100322W WO 9112765 A1 WO9112765 A1 WO 9112765A1
Authority
WO
WIPO (PCT)
Prior art keywords
monitor
tissue
thermal diffusion
diffusion flow
multiprobe system
Prior art date
Application number
PCT/US1991/000322
Other languages
English (en)
Inventor
Alexandros D. Powers
Original Assignee
Powers Alexandros D
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Powers Alexandros D filed Critical Powers Alexandros D
Publication of WO1991012765A1 publication Critical patent/WO1991012765A1/fr

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Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L19/00—Details of, or accessories for, apparatus for measuring steady or quasi-steady pressure of a fluent medium insofar as such details or accessories are not special to particular types of pressure gauges
    • G01L19/0092—Pressure sensor associated with other sensors, e.g. for measuring acceleration or temperature
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/02—Detecting, measuring or recording for evaluating the cardiovascular system, e.g. pulse, heart rate, blood pressure or blood flow
    • A61B5/026—Measuring blood flow
    • A61B5/0275—Measuring blood flow using tracers, e.g. dye dilution
    • A61B5/028—Measuring blood flow using tracers, e.g. dye dilution by thermo-dilution
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/03—Measuring fluid pressure within the body other than blood pressure, e.g. cerebral pressure ; Measuring pressure in body tissues or organs
    • A61B5/031—Intracranial pressure
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
    • G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
    • G01F1/68—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using thermal effects
    • G01F1/684—Structural arrangements; Mounting of elements, e.g. in relation to fluid flow
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
    • G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
    • G01F1/68—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using thermal effects
    • G01F1/684—Structural arrangements; Mounting of elements, e.g. in relation to fluid flow
    • G01F1/688—Structural arrangements; Mounting of elements, e.g. in relation to fluid flow using a particular type of heating, cooling or sensing element

Definitions

  • the present invention relates to devices which measure tissue blood flow, particularly those based on the thermal diffusion flow concept, measure tissue pressure and can also assess the function of human tissue through the simultaneous monitoring of critical physiological parameters.
  • Peltier stack In order for the Peltier stack to be able to detect flow (as determined by the rate of cooling) the tissue of interest needed to be exposed and uniform contact between the sensor and the tissue surface was required. Although Peltier stacks are widely used, the system suffers from its relatively large size of the sensor and the variability of its output.
  • MPTDFM thermal-diffusion flow monitor
  • the MPTDFM of the present invention uses an anemometer and is to be placed into the substance of the tissue itself through a very small surgical opening and does not require visual positioning.
  • the delivery system for the MPTDFM is one that is commonly used in medicine for the placement of various types of monitors, such as pressure monitors. It involves a small skin incision of approximately 1 cm, followed by opening of the connective tissue, such as by drilling a hole in bony coverings as would be required for access to the brain, and finally passage of the MPTDFM through this opening into the substance of the tissue. In this manner, the device can be placed quickly at the patient's bedside and a large operative procedure for visual positioning is not required.
  • the thermal diffusion flow monitor has better compatibility with pressure monitors as well as multiple parameter monitors in forming the MPTDFM for the detection and monitoring of biochemical substances.
  • use of an anemometer in the MPTDFM has the advantage of unexpected electrical properties. Specifically, the anemometer can be operated at a constant temperature mode with electrical current being supplied to the sensor. Thus, as the sensor tip of the anemometer is cooled by the blood flowing in the surrounding tissues, electricity will flow to the sensor to adjust it automatically. These changes in electrical current are then directly measured to produce a read- out. This direct measurement of the electrical current eliminates the need for additional circuitry that is required by other thermal monitoring designs which measure the temperature difference between a heat source and a temperature monitor.
  • FIGURE 1 illustrates a common thermal diffusion blood flow monitor mounted on a support structure
  • FIGURE 2 illustrates an embodiment of the MPTDFM.
  • FIGURE 3 illustrates a typical conical hot film probe used in the MPTDFM
  • FIGURE 4 illustrates one embodiment of the placement of multiple, single-point sensor tips onto a single probe
  • FIGURES 5a-5c illustrate embodiments of temperature gradient monitoring by multiple single- point sensor tips in a single probe
  • FIGURE 6a-6c illustrate embodiments to measure tissue pressure
  • FIGURE 7 illustrates one embodiment of the positioning of the MPTDFM probe into the substance of brain tissue
  • FIGURE 8 illustrates one embodiment of the MPTDFM with a side port placed on a catheter
  • FIGURE 9 illustrates an embodiment of the MPTDFM using an introducer.
  • a common thermal diffusion blood flow probe/pressure monitor 2 mounted on a flexible support structure 3 is shown.
  • the monitor 2 is based on a two-point system where a point 4 is a heat source and another point 6 measures the temperature of the tissue. Together, these two points, 4 and 6, form the sensor tip 8.
  • the sensor tip 8 is placed on the surface of the tissue to be monitored, with both points 4 and 6 requiring intimate contact.
  • the heat source 4 is then activated to a set temperature, generally 41° C, which is higher than the ambient temperature of the underlying tissue. As blood flows past this region, it cools the heated tissue. Thus, the temperature drop between the two points can be correlated with the rate of regional blood flow.
  • the measured temperature is 41" C
  • a reading of 35° C means that there is significant blood flow with a high degree of cooling.
  • the sensor tips are relatively large, so is the resulting thermal probe having dimensions typically 7 mm (width) by 5 mm (height) , including the sensor tip, support structure and wiring.
  • length of the probe is not of significance as the end of any probe must exit through the skin to be connected to a monitor by current connector 10.
  • the common thermal diffusion blood flow probe 2 described above can also be used to measure tissue pressure based on the transmission of pressure waves along a tube 12 filled with fluids.
  • One end 14 of the tube 12 is positioned such that it is surrounded by the natural fluids of the tissue. Pressure changes from the tissue are transmitted through the natural fluids, which then are directly transmitted to the fluids at the end of the tube. High tissue pressure causes the natural fluids to flow into the end of the tube, while low tissue pressure will extract fluids out of the end of the tube. This pressure differential causes a displacement of the fluids in the tube, which is then transmitted along the entire length of the tube.
  • a direct pressure is determined.
  • Measurements determined by this method are subject to significant error if the measuring/monitoring end 14 is obstructed with tissue. This is because although solids transmit pressure waves very well, the volume of solid tissue remains fairly constant over a wide range of pressures. Thus, despite wide variations in pressure there will be minimal displacement of fluids by tissue at the end 14 of the tube 12, leading to erroneous pressure determination at the monitoring end 16 of the tube. In contrast, the MPTDFM used in the present invention minimizes and/or eliminates completely this uncertainty in tissue pressure measurements and monitoring.
  • FIG. 2 shows an embodiment of the MPTDFM 18 of the present invention.
  • the MPTDFM 18 is formed by the combination of a thermal diffusion flow monitor 20, a pressure monitor 22, a multiple parameter monitor 24 and a support structure 26.
  • an anemometer to measure the rate of cooling of a solid has not been described before and the anemometer is generally used only when there is a continuous flow of material past the area of measurement (i.e., flowing fluid or stream of air) .
  • the combined use of an anemometer with different modalities in a single monitoring probe has not been commercially produced or experimentally described.
  • the thermal diffusion flow monitor 20 can be in the form of a conical hot film or hot wire probe 28 mounted on a catheter 30 with a diameter of 2 mm (FIG. 3) .
  • the probe 28 is a single-point sensor which acts as both a heat source and a temperature monitor.
  • the single point design reduces the size of the sensor tip 32 and also permits multiple sensor tips to be placed onto a single probe (FIG. 4) .
  • the sensor 34 of the conical hot film probe is usually made of nickel or platinum deposited in a thin layer onto a backing material 36, such as quartz, and connected to the electronic package by leads 38 attached to the end of the film. Double quartz protective coatings 40 are deposited over the thin film to prevent damage by abrasion or chemical reaction.
  • a single probe 42 with support structure 44 is shown to have multiple sensor tips 46 to simultaneously monitor blood flow at different tissue sites.
  • the array 48 of sensor tips 46 will more accurately reflect tissue blood flow by minimizing the sampling error associated with measurements made at a single site.
  • FIGS. 5a-c embodiments are shown in which temperature gradients are monitored by periodically altering the function of the single-point sensor tips 46 in the array 48.
  • a single-point sensor tip 46 functions as a heat source.
  • the remaining single-point sensor tips 50 then function as temperature monitors and are used to measure the temperature drop as distance d, increases from that heat source 46.
  • several single-point sensor tips 52-56 function as heat sources.
  • the remaining sensors 58 are used to measure the temperature drop over the intervening distances d 2 .
  • the entire array 48 of single-tip sensors are periodically heated.
  • the array 48 functions as if it were a wire which is being heated and is capable of monitoring its own rate of cooling.
  • a pressure transducer 22 with a movable diaphragm/strain gauge 60 is placed in contact with the tissue. As pressure changes are transmitted through the tissue, they will cause a displacement of this diaphragm/strain gauge 60 from its neutral position. The degree of change is then measured by one of two basic methods. In one method (FIG. 6b) , a pneumatic circuit 62 which pumps air into the pressure transducer 22 is used to counterbalance the tissue pressure causing the diaphragm/strain gauge to return to its neutral position. The pressure used to obtain this equilibrium is measured and directly correlated to the tissue pressure. In the second method (FIG.
  • a fiber optic cable 64 and a photodetector 66 are used.
  • light 61 emitted from the end of fiber optic cable 65 after incidence on a reflective surface 63 connected to the diaphragm 60, is perfectly aligned with the photodetector 66.
  • tissue pressure changes the diaphragm 60 is displaced, altering the alignment of the reflective surface 63 and thus the reflected light beam 67 with the photodetector 66.
  • the change in the light intensity measured at the photodetector 66 is transmitted through the sensor cable 64 to a readout.
  • the readout is directly related to tissue pressure.
  • the thermal diffusion monitors of the present invention can be made fully compatible with various types of pressure monitor systems.
  • ⁇ it may be advantageous to use a pressure monitor with a fluid filled column.
  • the multiple parameter monitors used in the present MPTDFM are well-known, and some modification thereof might be utilized without material effect upon the principle of the present invention. It should suffice to indicate that the types of multiple parameter monitor utilized in preferred embodiments of this invention include those temperature, oxygen and potential sensors (TOP Cat. No. M11199-19 probe) produced by OttoSensors Corporation, 11000 Cedar Avenue, Cleveland, Ohio 44106.
  • the support structure 26 for the MPTDFM 18 must be flexible, thermally inert, of a small size while still supporting the placement of multiple sensors and nonallergenic to biological tissues.
  • Materials for the fabrication of the support structure 26 are well-known and include various silicone based materials such as those used for medical catheters.
  • the MPTDFM probe 18 of the present invention is placed into the substance of the tissue (brain) 70 instead of onto the surface of the tissue.
  • the tissues 72 covering the organ-brain are the skin and the bones of the skull.
  • Hollow bolts 74 are used to hold the MPTDFM 18 in a stationary position in the tissue and permit exit of electrical wires 38 for attachment to external electrical components.
  • the tissue can be closed around the probe to provide anchoring instead of the use of bolts 74. Having the probe placed inside the tissue permits an easier method of sensor positioning and also dramatically reduces the chance of a poor contact between the thermal sensor tip 32 and the tissue 70, which is the major source of error with the earlier surface devices.
  • a sensor tip 32 may be advanced through a side port 76 of a suitable catheter 30 (FIG. 8) . In this design the sensor tip 32 is in a measuring position, completely surrounded by tissue.
  • an introducer 78 may be used (FIG. 9) .
  • the introducer 78 is essentially a cylindrical structure of greater diameter than the MPTDFM 18 itself. The introducer 78 is first inserted into the tissue. Once the introducer 78 is in position, the MPTDFM can be inserted through the center of the introducer. The introducer can then be removed and as the tissue returns to its original position, the MPTDFM sites on the probe will be surrounded.

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  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Medical Informatics (AREA)
  • Hematology (AREA)
  • Veterinary Medicine (AREA)
  • Public Health (AREA)
  • General Health & Medical Sciences (AREA)
  • Biophysics (AREA)
  • Pathology (AREA)
  • Fluid Mechanics (AREA)
  • Biomedical Technology (AREA)
  • Heart & Thoracic Surgery (AREA)
  • Animal Behavior & Ethology (AREA)
  • Molecular Biology (AREA)
  • Surgery (AREA)
  • Analytical Chemistry (AREA)
  • Chemical & Material Sciences (AREA)
  • Physiology (AREA)
  • Cardiology (AREA)
  • Neurosurgery (AREA)
  • Measuring Pulse, Heart Rate, Blood Pressure Or Blood Flow (AREA)
  • Measuring And Recording Apparatus For Diagnosis (AREA)

Abstract

L'invention se rapporte à une multisonde avec détecteur de flux à diffusion thermique (dit 'MPTDFM'), qui se caractérise par une amélioration de sa fiabilité, par une réduction de sa dimension hors tout, par une simplification du procédé de positionnement des capteurs, par une amélioration de sa compatibilité et de sa capacité à détecter le flux sanguin, la pression sanguine et d'autres paramètres physiologiques et critiques. On obtient une telle sonde MPTDFM en combinant un détecteur de flux à diffusion thermique (20), un détecteur de pression (22), un détecteur de paramètres multiples (24) et une structure de support (26).
PCT/US1991/000322 1990-03-02 1991-01-16 Multisondes avec detecteur de flux a diffusion thermique WO1991012765A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US48815390A 1990-03-02 1990-03-02
US488,153 1990-03-02

Publications (1)

Publication Number Publication Date
WO1991012765A1 true WO1991012765A1 (fr) 1991-09-05

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PCT/US1991/000322 WO1991012765A1 (fr) 1990-03-02 1991-01-16 Multisondes avec detecteur de flux a diffusion thermique

Country Status (5)

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EP (1) EP0517734A4 (fr)
JP (1) JPH05508328A (fr)
AU (1) AU7253591A (fr)
CA (1) CA2076667A1 (fr)
WO (1) WO1991012765A1 (fr)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0652420A1 (fr) * 1993-11-10 1995-05-10 Ksb S.A. Dispositif de mesure d'un fluide
WO1996022798A1 (fr) * 1995-01-25 1996-08-01 Wolfgang Fleckenstein Dispositif de retenue pour sondes de mesure de la pression sanguine cerebrale
WO2000020830A1 (fr) * 1998-10-06 2000-04-13 Trex Medical Corporation Sonde de detection de gradient de temperature utile pour surveiller des traitements medicaux hyperthermiques
WO2001021066A1 (fr) * 1999-09-24 2001-03-29 Ut-Battelle, Llc Dispositif implantable de surveillance de la pression des fluides intracraniens et cephalo-rachidiens
JP3231501B2 (ja) 1993-08-19 2001-11-26 株式会社日立製作所 Ｍｒｉ用内視鏡プローブ
EP1391646A3 (fr) * 2002-08-20 2005-03-02 Honeywell Technologies Sarl Soupape
US7077002B2 (en) 1999-12-17 2006-07-18 Per Sejrsen Method and an apparatus for measuring flow rates

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103561641B (zh) * 2011-06-01 2016-09-28 皇家飞利浦有限公司 用于分布式血流测量的系统
JP2017532079A (ja) * 2014-08-11 2017-11-02 ザ ボード オブ トラスティーズ オブ ザ ユニヴァーシ 温度及び熱輸送特性の分析のための表皮デバイス

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US4473081A (en) * 1980-05-14 1984-09-25 Consiglio Nazionale Delle Ricerche Multichannel programmable band comparator for apparatus used in cardiac surgery
US4554927A (en) * 1983-08-30 1985-11-26 Thermometrics Inc. Pressure and temperature sensor
US4660562A (en) * 1985-03-07 1987-04-28 House Sr Hugh A Multi-event biomedical electrode assembly
US4688577A (en) * 1986-02-10 1987-08-25 Bro William J Apparatus for and method of monitoring and controlling body-function parameters during intracranial observation
US4803992A (en) * 1980-10-28 1989-02-14 Lemelson Jerome H Electro-optical instruments and methods for producing same
US4809704A (en) * 1986-04-10 1989-03-07 Sumitomo Electric Industries, Ltd. Catheter type sensor
US4815471A (en) * 1988-08-01 1989-03-28 Precision Interconnect Corporation Catheter assembly
US4841981A (en) * 1986-03-07 1989-06-27 Terumo Corporation Catheters for measurement of cardiac output and blood flow velocity
US4850358A (en) * 1986-11-14 1989-07-25 Millar Instruments, Inc. Method and assembly for introducing multiple devices into a biological vessel
US4883062A (en) * 1988-04-25 1989-11-28 Medex, Inc. Temperture and pressure monitors utilizing interference filters
US4955380A (en) * 1988-12-15 1990-09-11 Massachusetts Institute Of Technology Flexible measurement probes
US4960109A (en) * 1988-06-21 1990-10-02 Massachusetts Institute Of Technology Multi-purpose temperature sensing probe for hyperthermia therapy

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DE2549559C3 (de) * 1975-11-05 1978-10-26 Draegerwerk Ag, 2400 Luebeck Einstichsonde zum Messen des Wärmeüberganges bzw. der Durchblutung leben- den Gewebes, insbesondere beim Menschen
US4741343A (en) * 1985-05-06 1988-05-03 Massachusetts Institute Of Technology Method and apparatus for measuring oxygen partial pressure and temperature in living tissue

Patent Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4473081A (en) * 1980-05-14 1984-09-25 Consiglio Nazionale Delle Ricerche Multichannel programmable band comparator for apparatus used in cardiac surgery
US4803992A (en) * 1980-10-28 1989-02-14 Lemelson Jerome H Electro-optical instruments and methods for producing same
US4554927A (en) * 1983-08-30 1985-11-26 Thermometrics Inc. Pressure and temperature sensor
US4660562A (en) * 1985-03-07 1987-04-28 House Sr Hugh A Multi-event biomedical electrode assembly
US4688577A (en) * 1986-02-10 1987-08-25 Bro William J Apparatus for and method of monitoring and controlling body-function parameters during intracranial observation
US4841981A (en) * 1986-03-07 1989-06-27 Terumo Corporation Catheters for measurement of cardiac output and blood flow velocity
US4809704A (en) * 1986-04-10 1989-03-07 Sumitomo Electric Industries, Ltd. Catheter type sensor
US4850358A (en) * 1986-11-14 1989-07-25 Millar Instruments, Inc. Method and assembly for introducing multiple devices into a biological vessel
US4883062A (en) * 1988-04-25 1989-11-28 Medex, Inc. Temperture and pressure monitors utilizing interference filters
US4960109A (en) * 1988-06-21 1990-10-02 Massachusetts Institute Of Technology Multi-purpose temperature sensing probe for hyperthermia therapy
US4815471A (en) * 1988-08-01 1989-03-28 Precision Interconnect Corporation Catheter assembly
US4955380A (en) * 1988-12-15 1990-09-11 Massachusetts Institute Of Technology Flexible measurement probes

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP0517734A4 *

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3231501B2 (ja) 1993-08-19 2001-11-26 株式会社日立製作所 Ｍｒｉ用内視鏡プローブ
EP0652420A1 (fr) * 1993-11-10 1995-05-10 Ksb S.A. Dispositif de mesure d'un fluide
FR2713764A1 (fr) * 1993-11-10 1995-06-16 Ksb Sa Dispositif de mesure d'un fluide.
WO1996022798A1 (fr) * 1995-01-25 1996-08-01 Wolfgang Fleckenstein Dispositif de retenue pour sondes de mesure de la pression sanguine cerebrale
US5891100A (en) * 1995-01-25 1999-04-06 Fleckenstein; Wolfgang Securing device for brain scan probes
WO2000020830A1 (fr) * 1998-10-06 2000-04-13 Trex Medical Corporation Sonde de detection de gradient de temperature utile pour surveiller des traitements medicaux hyperthermiques
WO2001021066A1 (fr) * 1999-09-24 2001-03-29 Ut-Battelle, Llc Dispositif implantable de surveillance de la pression des fluides intracraniens et cephalo-rachidiens
US6533733B1 (en) 1999-09-24 2003-03-18 Ut-Battelle, Llc Implantable device for in-vivo intracranial and cerebrospinal fluid pressure monitoring
US7621878B2 (en) 1999-09-24 2009-11-24 Ut-Battelle, Llc Implant for in-vivo parameter monitoring, processing and transmitting
US7077002B2 (en) 1999-12-17 2006-07-18 Per Sejrsen Method and an apparatus for measuring flow rates
EP1391646A3 (fr) * 2002-08-20 2005-03-02 Honeywell Technologies Sarl Soupape

Also Published As

Publication number Publication date
EP0517734A4 (en) 1993-01-13
CA2076667A1 (fr) 1991-09-03
EP0517734A1 (fr) 1992-12-16
AU7253591A (en) 1991-09-18
JPH05508328A (ja) 1993-11-25

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