WO2011080652A1 - Procédé et dispositif de mesure de signaux électromagnétiques d'un tissu - Google Patents

Procédé et dispositif de mesure de signaux électromagnétiques d'un tissu Download PDF

Info

Publication number
WO2011080652A1
WO2011080652A1 PCT/IB2010/055901 IB2010055901W WO2011080652A1 WO 2011080652 A1 WO2011080652 A1 WO 2011080652A1 IB 2010055901 W IB2010055901 W IB 2010055901W WO 2011080652 A1 WO2011080652 A1 WO 2011080652A1
Authority
WO
WIPO (PCT)
Prior art keywords
tissue
exciting coils
magnetic field
electromagnetic signals
conductivity
Prior art date
Application number
PCT/IB2010/055901
Other languages
English (en)
Inventor
Dayu Chen
Hua Jin
Ming Yan
Hui Liu
Original Assignee
Koninklijke Philips Electronics N.V.
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 Koninklijke Philips Electronics N.V. filed Critical Koninklijke Philips Electronics N.V.
Publication of WO2011080652A1 publication Critical patent/WO2011080652A1/fr

Links

Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/05—Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves 
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/05—Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves 
    • A61B5/053—Measuring electrical impedance or conductance of a portion of the body
    • A61B5/0531—Measuring skin impedance
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/44—Detecting, measuring or recording for evaluating the integumentary system, e.g. skin, hair or nails
    • A61B5/441—Skin evaluation, e.g. for skin disorder diagnosis
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/05—Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves 
    • A61B5/053—Measuring electrical impedance or conductance of a portion of the body

Definitions

  • the invention relates to a method and device for measuring a tissue, in particular, to a method and device for measuring electromagnetic signals of a tissue.
  • Electromagnetic signals of a tissue comprise some important property information of the tissue.
  • a well known technique is developed to measure water content of skin by measuring electromagnetic signals of the skin, and the electromagnetic signals are measured by placing a conventional electrode device on the skin.
  • the conventional electrode device comprises an exciting coil, such as a dipole coil, for generating a primary magnetic field and applying it to the skin, and a receiving coil for receiving electromagnetic signals induced by a secondary magnetic field which is generated by the skin in response to the primary magnetic field.
  • Fig. 1 schematically shows a dipole coil used in a conventional electrode device as an exciting coil.
  • a primary magnetic field 10 is applied to a skin of interest.
  • the dipole coil 11 exhibits a wide distribution of the magnetic field 10, which means that the measurement result of the conventional electrode device must be influenced by the property of other tissues which are not intended to be measured and which are far away from the dipole coil.
  • the other tissues can be other skins which are far away from the dipole coil and not intended to be measured.
  • the other tissue can also be some interior tissue of a body and situated far away from the dipole coil.
  • An object of this invention is to provide an improved device for measuring electromagnetic signals of a tissue.
  • the device for measuring electromagnetic signals of a tissue comprises at least two exciting coils for generating a primary magnetic field and applying it to the tissue, and adjacent exciting coils of each pair of exciting coils have opposite current flow, so that a distribution of the primary magnetic field is localized around the exciting coils.
  • the device also comprises at least one receiving coil for receiving electromagnetic signals induced by a secondary magnetic field, and the secondary magnetic field is generated by the tissue in response to the primary magnetic field.
  • the advantage is that the measurement result is less influenced by other tissues which are far away from the exciting coils.
  • the exciting coils comprise 2 n or 2n exciting coils, and n is an integer which is not less than 1.
  • the advantage is that the measurement result is more accurate.
  • the invention also provides a method of measuring electromagnetic signals of a tissue, and a computer program used in the method of measuring electromagnetic signals of a tissue.
  • Fig.1 schematically shows a dipole coil used in a conventional electrode device
  • Fig. 2 schematically shows a device for measuring electromagnetic signals of a tissue according to an embodiment of the invention.
  • Fig. 3 schematically shows a probe according to another embodiment of the device of Fig.
  • Fig. 4 schematically shows two exciting coils according to an example of an arrangement of exciting coils
  • Figs.5A-5G schematically show different examples of arrangements of exciting coils
  • Fig. 6 is a flowchart illustrating a method of measuring electromagnetic signals of the tissue according to an embodiment of the invention.
  • FIG. 2 schematically shows a device for measuring electromagnetic signals of a tissue according to an embodiment of the invention.
  • the device 1 for measuring electromagnetic signals of a tissue (not shown in the Figures) comprises at least two exciting coils 21 for generating a primary magnetic field and applying it to the tissue and at least one receiving coil 22 for receiving electromagnetic signals induced by a secondary magnetic field.
  • the secondary magnetic field is generated by the tissue in response to the primary magnetic field.
  • Adjacent exciting coils 21 of each pair of exciting coils 21 have opposite current flow, so that a distribution of the primary magnetic field is localized around the exciting coils 21.
  • the exciting coils 21 are arranged symmetrically in a plane. Each exciting coil 21 can be dependent on the rest of the exciting coils 21, but each exciting coil 21 is arranged close to/to connect to one or more adjacent exciting coils 21. Alternatively, the exciting coils 21 can be wound from a metal thread, so that each exciting coil 21 can connect to one or more adjacent exciting coils 21. Each exciting coil 21 generates a primary magnetic field which counteracts another primary magnetic field generated by one or more adjacent exciting coils, so that the primary magnetic field far away from the exciting coils 21 is almost cancelled and the primary magnetic field close to the exciting coils 21 is strengthened.
  • the exciting coils 21 are placed close to the tissue to be measured and the primary magnetic field is localized around the exciting coils 21, namely, the primary magnetic field is localized around the tissue to be measured.
  • the properties of other tissues which are far away from the exciting coils 21 will not impact the measurement result for the tissue to be measured.
  • the device 1 also comprises a processing unit 23 for processing the electromagnetic signals to acquire the conductivity of the tissue.
  • the processing unit 23 can acquire the conductivity of the tissue by checking a Q-factor (Quality-factor) of the receiving coil 22.
  • the processing unit 23 can also acquire the conductivity of the tissue, based on a resonant peak influenced by the tissue.
  • the processing unit 23 can further acquire the conductivity of the tissue, based on the mutual induction of the exciting coils.
  • the processing unit 23 is also used for comparing the conductivity with a
  • the pre-defined table is stored in a database
  • the pre-defined table comprises a set of conductivity ranges, and each conductivity range corresponds to a status. Each status may reflect a liquid content or tumor status of the tissue.
  • the liquid can be water, and the tumor status can be normal or abnormal.
  • the pre-defined table can be provided by a user or manufacturer of the device 1.
  • the tissue can be a skin or a tumor of a human or animal body.
  • the tissue is a skin of a body and the exciting coils 21 are placed close to the skin to be measured, the primary magnetic field being distributed over the skin (superficial layer of the skin). Only a very small primary magnetic field is distributed to the interior of the body or other skin parts far away from the exciting coils 21. Thus, the water content of the skin close to the exciting coils 21 can be measured with very little influence.
  • the device 1 further comprises an indicator 24 for indicating the conductivity of the tissue or the status of the tissue.
  • the indicator 24 can be a display for displaying the status or conductivity of the tissue, a speaker for announcing the status or conductivity of the tissue, or a light for showing the status or conductivity of the tissue by means of a different color.
  • the exciting coils 21 and the receiving coil 22 can be arranged in a probe 25.
  • the probe 25 is to be placed close to the tissue, so that the exciting coils 21 can generate the primary magnetic field and apply it to the tissue and the receiving coil 22 can receive the electromagnetic signals from the tissue.
  • the probe 25 is connected to the processing unit 23 by a cable 26.
  • the probe 25 is a flexible band-shape for receiving the exciting coils 21 and the receiving coil 22 therein.
  • Fig. 3 schematically shows a probe according to another embodiment of the device of Fig. 2.
  • the probe 25 is a pen-shape for receiving the exciting coils 21 and receiving coil 22 at one end of it.
  • the exciting coils 21 and the receiving coil 22 can be further embedded in a wrist.
  • the probe 25 can be placed close to the tissue directly, e.g. placed close to a skin of a body, to detect the water content of the skin.
  • the exciting coils 21 and receiving coil 22 can be mounted on a tip or a catheter of an endoscope, so as to measure electromagnetic signals of a tissue in a body, e.g. a tumor in a body, to detect the statuses (abnormal or normal) of the tumor.
  • the exciting coils 21 may comprise 2 n exciting coils, and n is an integer which is not less than 1.
  • Fig. 4 schematically shows two exciting coils according to an example of an arrangement of exciting coils. The direction of a current in an exciting coil 21 is opposite to the direction of a current in another exciting coil 21, so that the distribution of the primary magnetic field is localized around the two exciting coils 21.
  • Figs. 5A-5G schematically show different examples of an arrangement of exciting coils.
  • Figs. 5A to 5G "+" and "-" represent different magnetic field directions, respectively.
  • Fig. 5A shows four (2 2 ) circular exciting coils symmetrically arranged in a row.
  • Fig. 5B shows eight (23 ) circular exciting coils arranged in a row.
  • Fig. 5C shows eight (2 ) circular exciting coils arranged in two rows.
  • Fig. 5D shows sixteen (2 4 ) circular exciting coils.
  • Fig. 5E shows four (22 ) rectangular exciting coils.
  • Fig. 5F shows four (2 ) triangular exciting coils.
  • Fig. 5G shows multiple circular exciting coils (2 n ) arranged symmetrically in a plane.
  • the exciting coils may comprise 2n exciting coils, and n is an integer which is not less than 1.
  • Fig. 6 is a flowchart illustrating a method of measuring electromagnetic signals of a tissue according to an embodiment of the invention.
  • the method of measuring electromagnetic signals of a tissue comprises a step 61 and a step 62.
  • the step 61 is to generate a primary magnetic field and apply it to the tissue by means of at least two exciting coils. Adjacent exciting coils 21 of each pair of exciting coils 21 have opposite current flow, so that the distribution of the primary magnetic field is localized around the exciting coils 21.
  • the step 62 is to receive electromagnetic signals induced by a secondary magnetic field. The secondary magnetic field is generated by the tissue in response to the primary magnetic field.
  • the method also comprises a step 63 for processing the electromagnetic signals to acquire the conductivity of the tissue.
  • the step 63 may be intended to acquire the conductivity of the tissue by checking a Q-factor (Quality-factor) of the receiving coil 22.
  • the step 63 may be also intended to acquire the conductivity of the tissue, based on a resonant peak influenced by the tissue.
  • the step 63 may be further intended to acquire the conductivity of the tissue, based on a mutual induction of the exciting coils.
  • the step 63 is also intended to compare the conductivity with a pre-defined table to search a status for the tissue.
  • the pre-defined table is stored in a database (not shown in Fig. 1) of the device 1 , and the pre-defined table comprises a set of conductivity ranges and each conductivity range corresponds to a status. Each status may reflect a liquid content or tumor status of the tissue.
  • the liquid can be water, and the tumor status can be normal or abnormal.
  • the pre-defined table can be provided by a user or a manufacturer of the device 1.
  • a computer program is used in the method of measuring electromagnetic signals of a tissue.
  • the method comprises a step 61 and a step 62.
  • the step 61 is for generating a primary magnetic field and applying it to the tissue by at least two exciting coils 21. Adjacent exciting coils 21 of each pair of exciting coils 21 have opposite current flow, so that the distribution of the primary magnetic field is localized around the exciting coils 21.
  • the step 62 is for receiving electromagnetic signals induced by a secondary magnetic field. The secondary magnetic field is generated by the tissue in response to the primary magnetic field.

Landscapes

  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Heart & Thoracic Surgery (AREA)
  • Surgery (AREA)
  • Biophysics (AREA)
  • Pathology (AREA)
  • Engineering & Computer Science (AREA)
  • Biomedical Technology (AREA)
  • Veterinary Medicine (AREA)
  • Medical Informatics (AREA)
  • Molecular Biology (AREA)
  • Physics & Mathematics (AREA)
  • Animal Behavior & Ethology (AREA)
  • General Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Dermatology (AREA)
  • Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
  • Radiology & Medical Imaging (AREA)
  • Measurement And Recording Of Electrical Phenomena And Electrical Characteristics Of The Living Body (AREA)

Abstract

L'invention porte sur un dispositif et sur un procédé destinés à la mesure de signaux électromagnétiques d'un tissu. Le dispositif (1) comprend au moins deux bobines d'excitation (21) destinées à générer un champ magnétique primaire pour le tissu, et des bobines d'excitation adjacentes (21) à chaque paire de bobines d'excitation ont une intensité de courant opposée, afin que la répartition du champ magnétique primaire soit localisée autour des au moins deux bobines d'excitation (21). Le dispositif (1) comprend également au moins une bobine de réception (22) destinée à recevoir des signaux électromagnétiques induits par un champ magnétique secondaire, et le champ magnétique secondaire est généré par le tissu en réponse au champ magnétique primaire.
PCT/IB2010/055901 2009-12-30 2010-12-17 Procédé et dispositif de mesure de signaux électromagnétiques d'un tissu WO2011080652A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN200910263727 2009-12-30
CN200910263727.8 2009-12-30

Publications (1)

Publication Number Publication Date
WO2011080652A1 true WO2011080652A1 (fr) 2011-07-07

Family

ID=43857876

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/IB2010/055901 WO2011080652A1 (fr) 2009-12-30 2010-12-17 Procédé et dispositif de mesure de signaux électromagnétiques d'un tissu

Country Status (1)

Country Link
WO (1) WO2011080652A1 (fr)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20030055358A1 (en) * 2000-04-07 2003-03-20 Ko Harvey W. Apparatus for sensing human prostate tumor
WO2006129212A2 (fr) * 2005-05-31 2006-12-07 Philips Intellectual Property & Standards Gmbh Procede et appareil de mesure inductive de la bio-impedance du corps d'un utilisateur
WO2008078269A2 (fr) * 2006-12-20 2008-07-03 Philips Intellectual Property & Standards Gmbh Dispositif et procédé permettant d'influencer et/ou de détecter des particules magnétiques dans une zone d'action, et dispositif bobine

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20030055358A1 (en) * 2000-04-07 2003-03-20 Ko Harvey W. Apparatus for sensing human prostate tumor
WO2006129212A2 (fr) * 2005-05-31 2006-12-07 Philips Intellectual Property & Standards Gmbh Procede et appareil de mesure inductive de la bio-impedance du corps d'un utilisateur
WO2008078269A2 (fr) * 2006-12-20 2008-07-03 Philips Intellectual Property & Standards Gmbh Dispositif et procédé permettant d'influencer et/ou de détecter des particules magnétiques dans une zone d'action, et dispositif bobine

Similar Documents

Publication Publication Date Title
Nordbeck et al. Spatial distribution of RF‐induced E‐fields and implant heating in MRI
JP6710747B2 (ja) 位置追跡システム
Jambor et al. Evaluation of different mathematical models for diffusion‐weighted imaging of normal prostate and prostate cancer using high b‐values: a repeatability study
CN110074787B (zh) 检测用于手术指导的磁性标记物的***和方法
CA2390625C (fr) Dispositif medical avec capteur de position precis aux temperatures elevees
JP2579570B2 (ja) プローブシステム
Overall et al. Ensuring safety of implanted devices under MRI using reversed RF polarization
CN103782150B (zh) 用于监测柔性医疗器械的曲率的光学监测设备
US20120086449A1 (en) Magnetic resonance system and method for comprehensive implantable device safety tests and patient safety monitoring
US20110172512A1 (en) Method and system for magnetic induction tomography
Calcagnini et al. In vitro investigation of pacemaker lead heating induced by magnetic resonance imaging: role of implant geometry
WO2010092503A1 (fr) Procédé et dispositif de tomographie par induction magnétique
US20130310673A1 (en) Guide wire with position sensing electrodes
Detti et al. Assessment of radiofrequency self‐heating around a metallic wire with MR T1‐based thermometry
US20100171492A1 (en) Degradation and integrity measuring device for absorbable metal implants
Kaiser et al. Resonant marker design and fabrication techniques for device visualization during interventional magnetic resonance imaging
Godinez et al. Safe guidewire visualization using the modes of a PTx transmit array MR system
CN109541511A (zh) 温升预测方法和装置
Kocaturk et al. Active two‐channel 0.035 ″guidewire for interventional cardiovascular MRI
WO2011080652A1 (fr) Procédé et dispositif de mesure de signaux électromagnétiques d'un tissu
Hillenbrand et al. Toward rapid high resolution in vivo intravascular MRI: evaluation of vessel wall conspicuity in a porcine model using multiple imaging protocols
JP5379695B2 (ja) 作用の領域における磁気マーカーを配置するための方法及び配列
JP6595355B2 (ja) 磁心部材の劣化診断装置、磁心部材の劣化診断方法
US8321161B1 (en) Autonomous magnetic measurement system
WO2010097726A1 (fr) Système de tomographie à induction magnétique

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 10812915

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 10812915

Country of ref document: EP

Kind code of ref document: A1