The present invention relates to a cerebral local portion cooling probe and a cerebral mapping device using the probe.
When performing a neurosurgical treatment for patients with diseases such as brain disease, and intractable epilepsy, it is quite important to evaluate (or implement mapping of) local cerebral functions in individual patients in detail to avoid surgical complications.
At present, in order to detect limb movement function early, a technique is used in which an extent of resection is determined after a cerebral function (language area) mapping is performed with motor evoked potential (MEP) or surgery in a state where a patient is awakened.
Conventional cerebral function mapping is disclosed in Leading Edge Functional Neurosurgery (Chapter 9, “Brain and Spinal Cord Function Mapping”) published by Research Center for Medical Innovation and Technology on Jun. 20, 2002, pp. 329-339 (Non-Patent Documents 1) and in Nerve Monitoring Atlas for Neurosurgery, (Chapter 2, “Tumor Resection in Broca Language Area”) published by Igaku-Shoin on Feb. 1, 2003, pp. 29-36 (Non-Patent Document 2). In the conventional cerebral function mapping, cerebral local regions are electrically stimulated to perform cerebral function mapping in accordance with reactions in response to the electrical stimulation. In such a cerebral function mapping, there are some problems such as induction of convulsion fit due to the electrical stimulation and dispersion in analysis of measured results due to a setting of intensity of the electrical stimulation.
Also, it is disclosed in Sartorius C J, Berger M S: Rapid termination of intraoperative stimulation-evoked seizures with application of cold Ringer's lactate to the cortex. (J Neurosurg 88:349-351; 1998) (Non-Patent Document 3) that the convulsion fit is restricted by pouring cool water of 4° C. onto a brain surface in cerebral function mapping in an operation, when convulsion fit is induced by the electrical stimulation.
Further, devices for restricting convulsion fit by cooling the cerebral local regions are disclosed in Japanese Patent Application Laid-Open No. 2006-141993 (Patent Document 1) and Japanese Patent Application Laid-Open No. 2007-209523 (Patent Document 2). Also, devices that the inventor proposed are disclosed in Japanese Patent No. 3843054 (Patent Document 3) and Japanese Patent Application No. 2009-236290 (Patent Document 4).
Conventional cerebral function mapping was to evaluate and monitor cerebral function at local portions using electric stimulation, which induced convulsion fit due to the electric stimulation or generated dispersion in analysis of a measurement result due to setting of intensity of the electric stimulation. Actually, the electric stimulation often caused the convulsion fit in mapping of language area in a surgery where a patient is awakened. Accordingly, this was one of risks in the surgery where the patient is awakened and a problem highly necessary to be solved thereafter.
The present invention is to achieve the above described objects. The cerebral local portion cooling probe according to the present invention comprises: a handheld module having a tubular casing and cooling means and temperature detecting means which are provided in the tubular casing at a tip end thereof; and a cooling control unit controlling temperature of a local portion of a cerebral surface to a predetermined temperature in accordance with temperature detection signal from the temperature detecting means, with the tip end of the handheld module being caused to contact with a cerebral local portion in order to cool the cerebral surface to the predetermined temperature thereby monitoring a state of the cerebral local portion, wherein the cooling means provided in the tubular casing at the tip end thereof is a Peltier device, a coolant liquid circulating part is provided so as to contact with the heat generating surface on the rear side of the Peltier device, and the coolant liquid circulating part and a heat radiating part provided externally of the handheld module are coupled by conduits to circulate coolant liquid and radiate heat.
A metal plate may be provided at the front surface of the Peltier device and exposed as a tip end surface of the tubular casing and a thermocouple and a brain wave detecting electrode may be embedded in the metal plate as the temperature detecting means. In this case, the metal plate may be provided at the front surface of the Peltier device and exposed as the tip end surface of the tubular casing, and the thermocouple may be embedded in the metal plate as the temperature detecting means, and the metal plate may also be used as the brain wave detecting electrode.
Further, a cerebral function mapping device according to the present invention comprises: a mapping module accommodating a plurality of cooling modules in a casing so that cooling tip end surfaces of the cooling modules are arranged in a same plane, each of these cooling modules including a tubular casing, cooling means and temperature detecting means arranged in the tubular casing at the tip end thereof; a cooling control unit for controlling a temperature of a local portion of a brain surface at a predetermined temperature according to temperature detection signals from the temperature detecting means in selected one of the cooling modules of the mapping module; cooling module selecting means for selecting one of the plurality of cooling modules in the mapping module and causing only the selected one of the cooling modules to perform cooling operation; response inputting means for inputting information on responses of the cerebral local portion monitored in accordance with the cooling operation of the selected cooling module; and mapping data creating means for accumulating the information input by the response inputting means and creating mapping data.
The cooling means of the respective cooling modules in the mapping module are Peltier devices. A coolant liquid circulating part may be arranged to contact with the heat generating surface at the rear side of the Peltier device. An inflow conduit and an outflow conduit of coolant liquid connected to the coolant liquid circulating part in the plurality of cooling modules may be connected to any one of a cold liquid heat radiating part and a warm liquid heat radiating part. Cold liquid of the coolant liquid is circulated through the selected one of the cooling modules and warm liquid of the coolant liquid may be circulated through the other cooling modules so as to radiate heat at the cold liquid heat radiating part and the warm liquid heat radiating part respectively.
A metal plate may be provided at a front surface of the Peltier device of each of the cooling modules in the mapping module and exposed as a tip end surface of the tubular casing of each of the cooling modules. A thermocouple may be embedded in the metal plate as the temperature detecting means. Also, the metal plate at the tip end surface of each of the cooling modules of the mapping module can be used as a brain wave detecting electrode.
The cerebral local portion cooling probe and the cerebral function mapping device using the probe according to the present invention use means for cooling a cerebral local portion to monitor a state of the cerebral local portion without inducing convulsion fit as in a case where a cerebral function is evaluated using conventional electric stimulation. Accordingly, safety in monitoring the state of the cerebral local portion can be improved. Also, in mapping the cerebral function, safety and operability can be improved.
a) is a cross-sectional view showing inside of the handheld module M taken along a longitudinal plane and
A cerebral local portion cooling probe and a cerebral function mapping device according to the present invention will be described below. The cerebral local portion cooling probe monitors a brain by cooling cerebral local portions using a cooling handheld module and examining responses of the cerebral local portions to the cooling. The cerebral function mapping device includes and uses a mapping module, in which a plurality of cooling modules used for the cerebral local portion cooling probe are arranged integrally, to perform cerebral function mapping.
[Cerebral Local Portion Cooling Probe]
The heat radiating part A includes a reservoir and a circulating pump for coolant liquid circulation so as to radiate heat generated by the Peltier device in the handheld module M. The heat radiating part A is connected to the handheld module M via an inflow conduit and an outflow conduit. The control processing unit B is connected to the handheld module M and to the heat radiating part A via wirings respectively to control operation of the Peltier device in the handheld module M and to control processing of signals, receiving temperature signals detected by a temperature detecting element, brain wave signals or the like obtained in the handheld module M, thus controlling operation of the coolant liquid circulating pump in the heat radiating part A. As for the coolant liquid, physiological saline water, Ringer's solution, pure water or the like with relatively high specific heat and high biological safety are used.
a) shows the inside of the casing 1 of the handheld module M in a cross-sectional view taken along a longitudinal plane and
In
As shown in
The rear end wall part 1a closes the rear end part of the casing 1. The inflow conduit 5a the outflow conduit 5b and the wirings 8, 9 and 10 pass through the rear end wall part 1a. It is preferable that the size of the handheld module M with the cylindrical casing 1 and the rear end wall part 1a coupled together is of a length of 150 mm and an outer diameter 5 to 10 mm approximately. The inflow conduit 5a, the outflow conduit 5b and the wirings 8, 9, and 10 may be configured so that they can be attached to or detached from each other at the rear end wall part 1a or externally from the casing.
The control processing unit B includes a probe operation control unit 31, a coolant liquid circulation control unit 32, a switch and setting-inputting part 33 and a data processing unit 34. The probe operation control unit 31 is connected to the handheld module M via the wirings 8, 9, and 10 to receive the signals from the temperature detecting element 6 via the wiring 8 and the signals from the brain wave detecting electrode 7 via the wiring 9. The probe operation control unit 31 controls the operation of the Peltier device 2 via the wiring 10 to cool the cerebral local portion to a predetermined temperature on the basis of data obtained by performing A/D conversion on the detected temperature signals and transmits data related to temperature control to the coolant liquid circulation control unit 32, which data are used for controlling circulation of the coolant liquid to radiate heat generated by cooling operation of the Peltier device 2 through the coolant liquid circulating in the coolant liquid circulating part 4. Also, data on the basis of the signals from the brain wave detecting electrode 7 are transmitted to the data processing unit 34. The data processing unit 34 includes a control circuit for performing A/D conversion on the detected signals, controlling temperature and controlling operation of the Peltier device and the like. In
The coolant liquid circulation control unit 32 includes a control circuit for controlling operation of the coolant liquid circulating pump to circulate the coolant liquid in accordance with data related to temperature control transmitted from the probe control unit 31. The switch and setting-inputting part 33 includes keys for switching on/off of the operation of the whole cerebral local portion cooling probe and setting and inputting cooling temperature.
The cerebral local portion is efficiently cooled by radiating the heat generated due to the operation of the Peltier device 2 with the coolant liquid circulating through the coolant liquid circulating part 4. Even if power of the Peltier device 2 is turned off, the circulation of the coolant liquid is not simultaneously stopped, namely it is necessary to continue the circulation for about 3 to 5 minutes. A reason for this is to inhibit a rapid rise of temperature of the probe caused by stopping the circulation of the coolant liquid simultaneously.
In
The cerebral local portion cooling probe according to the present invention composed as described above drives the Peltier device to cool the cerebral local portion in a state where the coolant liquid circulates through the coolant liquid circulating part 4 in the handheld module so as to obtain a response to stimulation by cooling the cerebral local portion and monitor the state of the cerebral local portion.
The cerebral local portion cooling probe according to an embodiment of the present invention is used in a manner described as follows.
(a) Craniotomy is performed in a range necessary to monitor and excise lesion under general anesthesia.
(b) After completing the craniotomy, the anesthesia is discontinued to obtain an awakened state of a patient.
(c) Cerebral function is monitored with a focus on a language area or a motor area anatomically expected through making the tip end of the handheld module contact with the cerebral local portion and detecting brain wave signals with the tip end of the cerebral local portion cooling probe set at a predetermined temperature in an operating state of the probe.
In cooling, the temperature of the tip end of the handheld module is set at a predetermined temperature in a range of 5 to 15° C. and changes in neurological symptoms (a language function and a motor function of limbs) of the patient are observed before, during and after the cooling.
(d) The language function is evaluated according to naming of objects. The motor function is evaluated according to elevation of an upper limb and a lower limb, enclasping and unclasping of a hand and toe movement.
(e) Brain waves of cooled sites and around the cooled sites are measured and changes in electrical activity are also observed.
All of these measurements are completed in 60 minutes.
It is preferable to evaluate and set an optimum temperature and cooling period for effectively and efficiently performing these measurements using the cerebral local portion cooling probe.
[Cerebral Function Mapping Device]
A cerebral function mapping device uses a plurality of cooling modules similar to the handheld module used for cooling the local portion with the cerebral local portion cooling probe, in which a mapping module is composed so that the cooling tip end surfaces of the plurality of cooling modules are disposed in a matrix in a plane.
In
The composition for operating each mapping module MM includes a heat radiating part A and a control processing unit B basically in a manner similar to that of the cerebral local portion cooling probe as shown in
Wirings, representatively denoted by b11, b12, . . . , bmn, from the temperature detecting element and the brain wave detecting electrode of each of the cooling modules M11, M12, . . . , Mmn are respectively connected to a Peltier device operation control unit 41. Conduits (inflow conduits and outflow conduits), representatively denoted by c11, c12, . . . , cmn, from the coolant circulating part of each of the cooling modules M11, M12, . . . , Mmn are coupled with the flow path switch CV.
Flow paths are switched by the flow path switch CV so that the coolant liquid from the cool water heat radiating part Ac is circulated through the cooling module selected by switching the switch SW and the coolant liquid from the warm liquid heat radiating part Aw is circulated through the other cooling modules. The flow path switch CV is coupled with the warm liquid heat radiating part Aw by a warm liquid conduit cw, and is also coupled with the cold liquid heat radiating part Ac by a cold liquid conduit cc.
The flow path switch CV is configured as shown in
The joint FJ is of a fixed type, through which warm liquid flows in and out of the body part of the flow path switch CV. The joint RJ, as a rotary joint, is coupled with an end of a selecting and coupling conduit CT. The other end of the selecting and coupling conduit CT is coupled with a joint RC protruding internally at a position of a rotatable ring-shaped actuator R arranged at a lower side of the body part of the flow path switch CV, where the joint RC is formed so as to make cold liquid flow downward further. It is preferable that the selecting and coupling conduit CT is formed by a material with low heat conductivity.
A plurality of through holes h11, h12, . . . are formed at the lower end of the selecting and coupling conduit CT and on the same radial circumference. The inflow and outflow conduits c11, c12, . . . coupled with the cooling modules are coupled to lower ends of the through holes respectively. The ring-shaped actuator R is driven by a pulse motor or a ultrasonic motor and the conduit (inflow and outflow conduits c11, c12, . . . ) selected by a movement of the joint in a circumferential direction is coupled with the conduit cc through the selecting and coupling conduit CT. The other conduits that are not selected are coupled with the warm liquid conduit cw through an inside of the body part of the flow path switch CV.
When the selecting and coupling conduit CT coupled with the joint RC is brought into a position of a desired one of the through holes (any of the through holes h11, h12, . . . ) by rotation of the ring-shaped actuator R, the cold liquid from the cold liquid heat radiating part Ac is circulated through only the selected conduit (inflow and outflow conduits) and the warm liquid from the warm liquid heat radiating part Aw is circulated through the other conduits.
With the warm liquid heat radiating part Aw, coolant liquid at below or over 35° C. is circulated so that warm liquid at a temperature the same as that of the usual brain surface is normally circulated. With the cold liquid heat radiating part Ac, it is preferable that coolant liquid at a temperature of 5 to 15° C. is circulated to cool the cerebral local portion by the selected cooling module. Also, while the conduits c11, c12, . . . are representatively shown, a pair of conduits, i.e., an inflow conduit and an outflow conduit are provided for each cooling module so that the flow path switches CV corresponds to the pair of similar pair of conduits.
The body part of the flow path switch CV is for switching the circulations of the cold liquid and the warm liquid and not for reserve the liquid. Accordingly, the body part with a volume as little as possible is preferred. Also, the flow path switch CV operates to circulate the cold liquid only in the selected cooling module and the warm liquid in the other cooling modules. In an embodiment different from that described above, the cold liquid and the warm liquid can be switched and circulated by a changeover valve for each of the inflow conduits and the outflow conduits.
The control processing unit B includes the Peltier device operation control unit 41 for each of the cooling modules of the mapping module MM, the coolant liquid circulation control unit 42 and the data processing unit 43. The Peltier device operation control unit 41 has wirings b11, b12, . . . , bmn connected thereto from the temperature detecting element and the brain wave detecting electrode of each of the cooling modules, is connected to the Peltier device switch SW via a wiring d and to the flow path switch CV via a wiring g. The wiring d represents a wiring for receiving information related to the Peltier device selected by the switch SW and a wiring for supplying current for operation to the selected Peltier device.
The Peltier device operation control unit 41 receives the signals from each of the temperature detecting elements and the brain wave detecting electrodes via a wiring b (wirings b11, b12, . . . , bmn) from each of the cooling modules and supplies current for operating the selected Peltier device to the selected Peltier device so that the temperature of the cooled cerebral local portion related to the cooling module selected by the switch SW is a set value. Also, the rotation of the ring-shaped actuator R is controlled via the wiring g.
The coolant liquid circulation control unit 42 is to control operation of the coolant liquid circulating pump to circulate coolant liquid in accordance with data related to temperature control received by the Peltier device operation control unit 41. The coolant liquid circulation control unit 42 controls circulation of coolant liquid by the pump and the temperature of the coolant liquid in the warm liquid heat radiating part Aw via the wiring q. The coolant liquid circulation control unit 42 controls circulation of the coolant liquid by the pump and the temperature of the coolant liquid in the cold liquid heat radiating part Ac via the wiring p.
The cerebral local portion is efficiently cooled by radiating the heat generated due to the operation of the Peltier device 2 by the coolant liquid circulating through the coolant liquid circulating part 4. It is necessary that circulation of the coolant liquid is not stopped simultaneously after stopping the operation of the Peltier device but circulation of the coolant liquid is controlled to be continued for about 3 to 5 minutes. The reason for this is to inhibit a rapid rise of temperature of the probe caused by stopping the circulation of the coolant liquid simultaneously.
The temperature detection signals and the brain wave detection signals received by the Peltier device operation control unit 41 are transmitted to the data processing unit 43 in a form in which A/D conversion is performed and the data set and input by a setting-inputting board IB are transmitted to the data processing unit 43. The data processing unit 43 analyzes the data on the basis of the temperature detection signals and forms mapping data in accordance with the set and input data to accumulate and display the data on a display DP successively.
The setting-inputting board IB is used for selecting and inputting the inspection items or the like in mapping and configured to be a form as shown in
As for the inspection items in the central field in
An arrangement of setting and inputting buttons in the setting and inputting board IB is in accordance with the contents such as inspection items by the cerebral function mapping device. The buttons for selecting cooling modules in the left field are in accordance with the arrangement and configuration of the cooling modules and the buttons for inspection items or responses are also arranged in accordance with their applied forms. The setting-inputting buttons may be in a form of a snap-type button or a touch-screen. In lower fields of the setting-inputting board, on/off switch for operation of the mapping device and a temperature setting part in cooling by the mapping module are arranged.
Functions of the setting-inputting board IB are realized in a form of hardware such as keys or buttons to be operated as well as in a form of software in which a program related to control of the cerebral function mapping device is formed so that a layout of predetermined operation items as the setting-inputting board is displayed on a display screen and the setting and inputting may be performed according to the key operations on a computer.
The operation procedure of the cerebral function mapping with the cerebral function mapping device configured as described above may be performed via similar steps in a case where the state of the cerebral local portion is monitored by the cerebral local portion cooling probe.
That is, the procedure is performed by steps of:
(a) Craniotomy is performed in a range necessary to map and excise lesion under general anesthesia.
(b) After completing the craniotomy, the anesthesia is discontinued to obtain an awakened state of a patient.
(c) Cerebral function is mapped with a focus on a language area or a motor area anatomically expected through making the tip end of the mapping module contact with the cerebral local portion and detecting brain wave signals with the cerebral local portion cooling probe set at a predetermined temperature in an operating state of the mapping module.
In cooling, the temperature of the tip ends of the cooling modules of the mapping module are set at a predetermined temperature in a range of 5 to 15° C. and changes in neurological symptoms (a language function and a motor function of limbs) of the patient are observed before, during and after the cooling.
(d) The language function is evaluated according to naming of objects. The motor function is evaluated according to elevation of an upper limb and a lower limb, enclasping and unclasping of a hand and toe movement.
(e) Brain waves of cooled sites and around the cooled sites are measured and changes in electrical activity are also observed.
In mapping, the cerebral function mapping device is launched by turning the on/off switch of the device in the setting and inputting board IB and the temperature of cooling by the mapping module is set by the temperature setting part. The temperature of the cooled cerebral local portion with respect to the set temperature is controlled by the operation of the Peltier device and the circulation of coolant liquid so that the result is displayed on the display. After confirming that temperature is the predetermined, the mapping is performed by using the mapping module.
First, one of the cooling modules M11, M12, . . . , Mmn is selected and specified by the button of the inspection position so that the Peltier device with respect to only the specified cooling module is in a cooling operation state and cold liquid is in a circulation state, while the Peltier devices of the other cooling modules are in a non-operation state and warm liquid is in a circulation state. In such states of the mapping module, the responses of a subject are successively examined. In this operation, when the cooling probe M11 is specified, a response of a right hand is examined to push down a “right hand” button so as to input presence or absence of the response and normal or abnormal state of the right hand by pressing the buttons of response. In such operations, responses with respect to inspection items such as a left hand, a right foot or the like are successively examined and input by the buttons of response.
Data input as inspection items with the respective cooling modules and responses to the items are successively stored in a memory of the data processing unit so that the data of responses to the inspection items obtained with the whole cooling modules M11, M12, . . . , Mmn result in cerebral function mapping data.
The cerebral local portion cooling probe and the mapping device configured to include a plurality of the cooling modules according to the present invention are to operate the cooling means to perform cooling as stimulation to obtain a response with high safety and reliability without inducing convulsion fit as in a case where electrodes are used to cause stimulation.
Number | Date | Country | Kind |
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2010-071321 | Mar 2010 | JP | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/JP2011/057424 | 3/25/2011 | WO | 00 | 12/7/2012 |