JP2004513681A - Apparatus and method for measuring and communicating biological parameters - Google Patents

Abstract

Disclosed are devices and methods for measuring and communicating parameters of the brain, tissue or other organs. The invention includes a sensor for detecting a parameter of interest. Preferably, the sensor is located at the far end of the probe. In a preferred embodiment, the sensor is part of a passive system that allows pressure or temperature measurements to be taken and communication of the measurements to the attending physician when the passive system receives power from an external power source. In another embodiment, the sensor is a system having a long-term energy source and a storage system that allows pressure or temperature measurements to be taken regularly or on demand, and then communicates the measurements to the attending physician as desired. Part. The invention also includes, in one embodiment, a method of measuring and communicating parameters of a brain, tissue, or other organ. The method includes providing a sensor that senses a parameter of interest; implanting the sensor in or near a brain, tissue, or other organ capable of sensing the parameter of interest; Providing a reactor capable of displaying, processing or taking action; sensing a parameter of interest; communicating the sensed parameter to the reactor; displaying the parameter or Processing or taking action in response to the parameter.

Description

[0001]
(Technical field to which the invention belongs)
The present invention relates to devices and methods for measuring and communicating parameters of the brain, tissue or other organs, particularly intracranial pressure or temperature or both in the brain.
[0002]
(Conventional technology)
A typical adult has a total of about 120-150 cc (cerebrospinal fluid) CSF in about 25 cc ventricles in the brain. A typical adult also produces about 500 cc / day of CSF, all of which is continuously reabsorbed into the bloodstream.
[0003]
A variety of conditions can cause the pressure of the CSF to fluctuate, often elevated and dangerous. For example, hydrocephalus is a condition of excessive accumulation of CSF in the ventricles or cavities of the brain. Hydrocephalus can arise from congenital conditions that impede normal CSF circulation or as a result of problems in CSF reabsorption.
[0004]
Excessive accumulation of CSF due to hydrocephalus causes increased pressure on the brain. Whatever the cause, over time, increased CSF pressure damages brain tissue. Shorting excess CSF to another area of the body has been shown to be therapeutically beneficial and generally leads the patient to a complete and active life.
[0005]
To treat hydrocephalic conditions, shunts are used as a conduit to transport CSF from a location in the body, for example, to the peritoneal cavity or atrium. A typical shunt for transferring CSF from the ventricle to another part of the body consists of a ventricular catheter, a valve and a distal catheter. CSF shunts also exist to transport fluid from the spine to another part of the body, such as the peritoneal cavity.
[0006]
Examples of systems that continuously exhaust excess CSF from the ventricles are manufactured and sold by Medtronic PS Medical of Goleta, Calif., And Rudolf R. Schulte, Geari P. East, Marga on December 24, 1985 -There is a Delta (R) shunt and CSF-flow control shunt assembly disclosed in U.S. Patent No. 4,560,375 entitled "Flow Control Valve" to M. Bryant and Alphonse Heindl. Such a system uses a drainage catheter 2 placed in the ventricle 4 in the patient's brain (FIG. 1). The drainage catheter 2 is connected to the valve 6. A ventricular or atrial catheter 8 is connected to the valve 6. A peritoneal cavity or atrial catheter 8 is placed in the patient's peritoneum or atria, respectively, to drain excess CSF. All of these systems continuously transfer excess CSF from the patient's ventricle through the drainage catheter 2 to another part of the body. For patients with head trauma, often with increased intracranial pressure for at least a period of time, it is often desirable to continuously discharge CSF to an external device, usually to maintain normal CSF pressure in the brain.
[0007]
Examples of systems that continuously exhaust excess CSF to external devices include the Becker System® and EDM Drainage System® manufactured and sold by Medtronic PS Medical of Goleta, California. Another example of a system for continuously discharging excess CSF is U.S. Pat. No. 4,731,056, entitled "External Drainage Antisphon Device," issued to William S. Tremulis on March 15, 1988. It is shown. A further such system is disclosed in U.S. Pat. No. 5, entitled "External Drainage Shunt," issued to John A. Kruger, Kevin M. Jager, and Helmut WC Rosenberg on June 30, 1998. , 772,625.
[0008]
(Summary of the Invention)
An apparatus for measuring and communicating parameters of a brain, tissue or other organ is disclosed. The present invention can detect a parameter of interest and then communicate the detected parameter to an external device, where the parameter can be displayed, processed, or acted upon. The present invention allows for long-term and stable measurement and communication of physiological parameters. In a preferred embodiment, the device measures and communicates parameters of the brain, tissue, or other organ. In particular, an apparatus for measuring and communicating intracranial pressure, pressure or temperature of CSF in brain, tissue or other organs is disclosed.
[0009]
The present invention includes sensors that sense pressure, intracranial pressure, CSF pressure or temperature. The sensor is preferably located distal to the probe and is preferably located in the region of the brain, tissue or other organ where measurement is desired, such as the brain parenchyma or ventricle.
[0010]
In a preferred embodiment, the sensor is part of a passive system that makes pressure or temperature measurements and communicates to the attending physician when the passive system receives power from an external power source. The portion of the passive system that receives power from an external power source and communicates pressure measurements is preferably located at or next to the patient's skull, and the sensors are located at or near the area where measurements are desired to be taken.
[0011]
The passive system couples to external devices that provide power to the passive system. This power is used to activate the sensing operation of the sensor and upload the sensed information from the passive system to an external device. As a result, when coupled to an external power source, the passive system can measure and uplink measured physiological parameters, such as pressure and temperature measurements, from the sensors to the external device.
[0012]
In another embodiment, the sensor is a system having a long-term energy source and a system that allows pressure or temperature measurements to be taken periodically or on demand, stores the measurements, and then communicates to the attending physician as desired. Department. The portion of the system that provides power, stores pressure or temperature measurements, and communicates pressure or temperature measurements is preferably located at or adjacent to the patient's subclavian site.
[0013]
The long-term energy source can be rechargeable. This power from the long-term energy source is used to activate the sensing operation of the sensor, store pressure or temperature measurements, and upload the sensed pressure or temperature information from the system to an external device.
[0014]
In another embodiment of the invention, the sensed parameters are used to control a pump or valve of a CSF shunt or drainage system. In this embodiment, the pump or valve is positioned between a catheter located in the ventricle and a shunt used as a conduit to transport CSF from one location in the body to another. In response to the sensed CSF pressure, the pump operates to pump CSF fluid or the valve opens to drain CSF fluid.
[0015]
In one embodiment, the invention also includes a method for measuring and communicating parameters of a brain, tissue or other organ. The method comprises providing a sensor for sensing a parameter of interest; implanting the sensor in or near a target of a brain, tissue or other organ capable of sensing the parameter of interest; Providing a reaction device capable of displaying, processing or taking action, sensing a parameter of interest, communicating the detected parameter to the reaction device, displaying or displaying the parameter. Processing or taking action in response to the parameter. In one embodiment of the method, the parameter of interest is intracranial pressure, pressure or temperature of CSF in the brain, tissue or other organ. Also, in another embodiment of the method, providing the sensor comprises providing the sensor as described herein. Further, in another embodiment of the invention, the method includes providing a CSF shunt or drainage system having a pump or valve; and causing the device to take action in response to the parameter comprises controlling the pump or valve; including.
[0016]
Another object of one embodiment of the present invention is a system and method for measuring a physiological parameter such as pressure, intracranial pressure, CSF pressure or temperature without requiring a continuous power source such as a battery or power capacitor. To provide.
[0017]
It is another object of one embodiment of the present invention to provide an apparatus and method for communicating sensed physiological parameters, such as pressure and temperature measurements, to an external device.
[0018]
In another embodiment of the present invention, it is an object of the present invention to provide a system and method for storing sensed physiological parameters, such as sensed pressure or temperature measurements, that are later uploaded to an external device. .
[0019]
In yet another embodiment of the present invention, it is an object of the present invention to provide systems and methods that allow for active action in response to a sensed physiological parameter. In particular, in another embodiment of the present invention, an object of the present invention is to provide information actively to adjust such a shunt or drainage system in response to CSF shunt or drainage systems and CSF pressure measurements. It is to be.
[0020]
In another embodiment of the present invention, an object of the present invention requires a single incision of the tissue to implant the sensor, which is then closed and achieves long-term monitoring of the parameter of interest in the implanted sensor. It is to provide a sensor for physiological parameters, in particular for brain parameters, which makes it possible to treat.
[0021]
It is an object of the present invention in another embodiment of the present invention to provide an implantable device that provides information about a biological parameter of interest that operates independently of the battery and thus continues to operate independent of battery life. It is to be.
[0022]
These and other objects of the invention will become apparent from the description of the invention contained herein and more particularly to the accompanying drawings. Throughout the description, like elements are referred to by like reference numerals. Further, it will be apparent to one skilled in the art that modifications to the description contained herein may be made and still fall within the scope of the invention. Further, it should be apparent that the methods of the present invention can be performed by the systems or devices presented or can be performed by other systems and devices that will be apparent to those skilled in the art. Accordingly, implementation of the method is not intended to be limited to implementation by the particular systems and devices presented.
[0023]
(Detailed description of the invention)
An apparatus embodying the present invention is shown in FIG. 2 and is generally designated as 10. Device 10 includes an implanted probe 12 and an external device 14. Probe 12 includes a sensor 16, probe electronics 18 and a probe coil 20. The external device 14 includes an external coil 22, an external electronic circuit 24, a power supply 26, and a user communication system 28.
[0024]
In the preferred embodiment of the present invention shown in FIGS. 3 and 4, probe 12 includes a near end 30, a far end 32, and a central axis. Sensor 16 is preferably located at far end 32. The sensor 16 is a sensor capable of detecting a pressure such as an intracranial pressure. One example of such a sensor is U.S. Pat. No. 9 filed by Keith A. Misel and Lee Styros, entitled "Intractual Monitoring and Therapy Delivery Control Device, System and Method", assigned to the same assignee as the present invention. / 299,774.
[0025]
The probe head 36 is disposed at the near end 30. In a preferred embodiment, the probe head 36 is generally disc-shaped in shape and includes the implanted probe coil 20. The probe coil 20 is an inductive coil. In one embodiment, shown in FIGS. 3 and 4, the probe coil 20 is wound around an axis 34 in the plane of the probe head 36. The probe head 36 includes a lower surface 38 and an outer edge 40.
[0026]
In the embodiment of FIGS. 3 and 4, the probe electronics 18 is housed in an electronics case 42 mounted on the underside 38 of the probe head 36. The electronic circuit case 42 has a peripheral surface 44 and a lower surface 46. The electronic circuit case 42 is preferably cylindrical with a smaller diameter about the axis 34 than the probe head 36.
[0027]
As shown in FIGS. 3 and 4, the sensor 16 is separated from the electronic circuit case 42. This is preferably achieved by disposing the sensor 16 at the far end of a body 48 connected to the lower surface 46 of the electronic circuit case 42. The body 48 can be made from a rigid material, such as a rigid biocompatible plastic such as titanium or polyurethane. Alternatively, body 48 may be made from a flexible material, such as a soft, body-compatible plastic, such as polyurethane, which is inherently soft by its composition or designed to be soft by its structural design. it can. In either the rigid or flexible case, the material of the body 48 may be a metal, plastic that is both body-compatible and, as is well understood in the art, flexible or rigid to varying degrees as desired. , Ceramic or other material.
[0028]
In embodiments where the body is rigid, the sensor 16 is located in a fixed position relative to the electronics case 42. If the body 48 is flexible, as in the embodiment shown in FIG. 9, the sensor 16 can be placed at a desired location in the brain, tissue or other organ anywhere within the body. In particular, when the main body 48 is flexible, the sensor 16 can be arranged at a location where the distance from the sensor 16 to the electronic circuit case 42 changes due to, for example, movement.
[0029]
Further, when the main body 48 is flexible, the sensor 16 can be arranged in an area where the sensor 16 is difficult to arrange when the main body 48 is rigid. For example, if the body 48 is flexible, the sensor 16 can be "slid" between the dura and the skull to a desired position between the dura and the skull.
[0030]
In yet another embodiment, the sensor 16 can be connected to the electronics case 42 via a system known as a "body bus." A “body bath” is a telemetry system in which the patient's own body provides the interconnection between sensor 16 and electronics case 42. Examples of such "body bus" communication systems were published on January 29, 1991 and May 19, 1992 to Hermann D. Funke, and each of "Body Bus Medical Device Communication System" and "Acoustic Body Bus". Nos. 4,987,897 and 5,113,859, entitled "Medical Device Communication System", the teachings of which are incorporated herein by reference in their entirety. Alternatively, the sensor 16 can be linked to the electronics case 42 using the radio frequency telemetry method described in Gedeke US Pat. No. 5,683,432.
[0031]
Sensor 16 is preferably calibrated at the manufacturing site by comparing its measurements to measurements from standardized sensors. External devices 14, sensors 16, and probe electronics 18 for the purpose of calculating a calibration factor unique to each sensor 16 and post-processing to achieve an accurate report of the physiological parameter measured by the sensor 16. , In the storage device 78 or the microprocessor 102.
[0032]
Since the probe 12 is inserted into a living body, the probe 12 must be hermetically sealed in order to prevent body fluid from entering the probe 12.
[0033]
In the more preferred embodiment shown in FIGS. 3 and 4, the proximal end 30 is located just outside the patient's skull 50 or is incorporated within the skull 50. This is preferably accomplished by creating a larger diameter probe head 36 that electronics case 42 has about axis 34. Next, a hole 52 having a diameter approximately equal to the diameter of the electronic circuit case 42 (FIG. 5) is formed in the skull 50 in order to dispose the probe 12. Hole 52 must extend completely through skull 50 and have the same diameter as the diameter of electronic circuit case 42. The sensor 16 and the body 48 of the probe 12 are placed in the hole 52 until the electronic circuit case 42 contacts the hole 52. The electronic circuit case 42 is then aligned with the hole 52 and pushed into the hole 52 until the lower surface 38 of the probe head 36 contacts the skull 50. The electronics case 42 must be dimensioned so that it does not extend completely into the hole 52.
[0034]
Alternatively, threads can be placed around the peripheral surface 44 of the electronic circuit case 42. In the present embodiment, the hole 52 is a screw hole having a screw thread that matches the screw thread of the electronic circuit case 42. The electronic circuit case 42 is brought into contact with the hole 52 as described above. However, instead of pushing the electronic circuit case 42 into the hole 52, the electronic circuit case 42 is screwed into the hole 52.
[0035]
In yet another embodiment, shown in FIG. 6, threads are located on the outer edge 40 of the probe head 36. Hole 52 is sized to have a diameter approximately the same as the diameter of probe head 36. Also in this embodiment, the hole 52 has a thread corresponding to the thread of the probe head 36. To place the probe 12, the sensor 16, the body 48 and the electronic circuit case 42 of the probe 12 are placed in the hole 52 until the outer edge 40 of the probe head 36 contacts the hole 52. The probe head 36 is then aligned with the hole 52 and screwed into the hole 52 until the probe head 36 is in the desired orientation, for example flush with the skull 50. In this embodiment, the electronic circuit case 42 may or may not have the same diameter as the probe head 36.
[0036]
In another embodiment shown in FIG. 7, the probe head 36 is connected to the electronic circuit case 42 but is separated therefrom. In this embodiment, the electronics case 42 is mounted through a hole 52 drilled in the skull 50, and the body 48 and the sensor 16 are still mounted on the electronics case 42 by all of the variations described herein. However, in this embodiment, the probe head 36 and the probe coil 20 are implanted under the patient's skin rather than on or within the skull 50. The probe head 36 can be attached to the patient's skull 50 by screws, adhesive, or other means as will occur to those skilled in the art. Alternatively, a hole separate from hole 52 can be made in skull 50 to receive probe head 36. If the probe head 36 is located in another hole, the probe head 36 may have a thread located on the outer edge 40 of the probe head 36, and the other hole may have a thread corresponding to the thread on the probe head 36. It has a peak and is dimensioned to have a diameter approximately the same as the diameter of the probe head 36. In the present embodiment, in order to dispose the probe 12, the sensor 16, the main body 48, and the electronic circuit case 42 of the probe 12 are disposed in the hole 52. Next, the probe head 36 is attached to the skull 50 as described above.
[0037]
In a further embodiment, shown in FIGS. 8 and 9, a bar hole ring 54 having an opening 56 of diameter “A” is placed in the hole 52 of the skull 50. Burr ring 54 can be screwed into the bone of skull 50 or otherwise attached to skull 50 as is well known for bur holes. In this embodiment, the probe head 36 has a diameter that is approximately equal to the diameter “A” of the opening 56 in the bar hole ring 54. The probe head 36 is positioned within an opening 56 that can be positioned in place by means such as friction, biocompatible adhesive, or other means as will occur to those skilled in the art.
[0038]
In the embodiment of FIG. 8, the body 16 is rigid so that the sensor 16 is disposed at a fixed distance or fixed relationship from the probe head 36. In the embodiment of FIG. 9, the body 48 is flexible. In this embodiment, sensor 16 is positioned at the desired location through opening 56.
[0039]
In a further embodiment, shown in FIG. 10, the probe head 36 may include all or part of the probe electronics 18. In this embodiment, there is no need to have the electronic circuit case 42. Thus, the sensor 16 can be mounted directly to the probe head 36 through a rigid or flexible body 48. In use, a hole 52 is drilled in the skull 50 and the sensor 16 is positioned at a desired location from the hole 52. The probe head 36 can then be attached to the skull 50 as described above.
[0040]
In a variation of this embodiment, the probe head 36 can be located away from the hole 52. For example, the probe head can be placed at a common site for placing an implantable neurological simulator with RF power below the skin below the clavicle or abdomen. In this embodiment, it is necessary to position the body 48 on the skull 50 using a bar hole ring so that the sensor 16 does not move relative to the hole 52. Further, in any of the embodiments described herein, the probe electronics may be located wholly or partially within the body 48.
[0041]
Probe electronics 18 includes sensor electronics 58 and transmitter 60. The sensor electronics 58 is connected to the sensor 16, provides power to the sensor 16, instructs the sensor 16 to take a measurement, processes the detected measurement signal from the sensor 16, and converts the detected signal into a digital signal Convert to The digital signal is preferably passed to a transmitter 60.
[0042]
The transmitter 60 is connected to the sensor electronics 58 and the probe coil 20. The probe coil 20 acts as an antenna as described below. The transmitter 60 and the probe coil 20 communicate the pressure and temperature information determined by the sensor 16 to the external device 14 by telemetry. An example of a telemetry system is the "Adaptive, Performance-Optimizing Communication System," issued November 4, 1997 to Stephen D. Gödeke, Gregory J. Hublich, John G. Kaymel, and David L. Thompson. U.S. Pat. No. 5,683,432 entitled "Communicating with an Implanted Medical Device"; Issued "World Wide Patient Location and Data Telemetry System for Implant" US Patent No. 5,752,976, entitled "Ble Medical Devices," issued December 1, 1998 to Stephen D. Gödeke, Gregory J. Howbrich, John L. Kaymel, and David L. Thompson. U.S. Pat. No. 5,843,139, issued on May 18, 1999, entitled "Adaptive, Performance-Optimizing Communication System for Communicating with an Implanted Medical Device," and US Pat. No. 5,843,139 issued May 18, 1999. U.S. Patent No. 5,904,70 entitled "Deriving Relative Physiological Signals". It is shown in No., incorporated in their entirety teachings herein by reference. Other alternatives for communication between the probe 12 and the external device 14 include amplitude shift keying (ASK), two-phase shift key (BPSK), or four-phase shift key (QPSK), to name a few.
[0043]
In a further preferred embodiment, the probe electronics 18 includes an AC / DC conversion system 62 (FIG. 11). The probe coil 20 is connected to an AC / DC conversion system 62. The probe electronics 18 enables power to be transferred from the external device 14 to the probe to energize the probe 12 and simultaneously uplink the physiological parameters sensed by the probe 12 from the probe 12 to the external device 14. enable. This simultaneous power transmission and information uplink is preferably performed by a technique known as absorption modulation, as is well understood by those skilled in the art.
[0044]
In this embodiment, the AC / DC conversion system 62 includes a rectifier 66 and a regulator 68. Probe coil 20 is inductively coupled to external coil 22 of external device 14, as described below. This inductive coupling between the probe coil 20 and the outer coil 22 provides power to the probe coil 20. This power takes the form of an alternating current. In the preferred embodiment, this AC current has a frequency of about 175 kHz, but other frequencies can be used if desired.
[0045]
The rectifier 66 is connected to the probe coil 20 and converts AC power received from the probe coil 20 into DC power. Rectifier 66 is preferably a full-wave rectifier, which is well understood in the art, but may be any other rectification system that is also well understood in the art. The DC power is passed to a regulator 68 that ensures a relatively constant DC level, for example, despite variations in power received from the probe coil 20 due to relative movement of the probe coil 20 with respect to the external coil 22. In this manner, regulated DC power is provided to energize the probe electronics 18.
[0046]
In another embodiment (FIG. 12), the probe electronics 18 includes the AC / DC conversion system 62 described above, and further includes a temporary energy source 64. The probe coil 20 is connected to the AC / DC conversion system 62 again. Probe coil 20 is inductively coupled to external coil 22.
[0047]
In this embodiment, the temporary energy source 64 is connected to the AC / DC conversion system 62. Temporary energy source 64 preferably takes the form of a rechargeable battery or a power capacitor, such as a "supercapacitor" having a small capacity, such as 1 f, but larger or more as desired. Small volumes can be used.
[0048]
The inductive coupling between probe coil 20 and external coil 22 provides power to probe coil 20 and charges temporary energy source 64 through AC / DC conversion system 62. Temporary energy source 64 then provides energy to energize probe electronics 18.
[0049]
The probe coil 20 in the preferred embodiment (FIG. 11) also acts as an antenna connected to the transmitter 60 for transmitting information from the sensor 16 to the external device 14. In this role, the probe coil 20 acts as an antenna in addition to acting as an induction coil for receiving power from the external device 14 as described above. As described above, since the probe coil 20 is a coil, when the probe coil 20 functions as an antenna, the probe coil 20 becomes a coil antenna.
[0050]
In a preferred embodiment, the probe coil 20 performs both the function of inductively coupling with the external 22 to receive power from the external device 14 and the function of transmitting information from the transmitter 60 to the external device 14. In another embodiment, shown in FIG. 13, these two functions are separated. In this alternative embodiment, the probe coil 20 inductively couples with the external coil 22 to perform only the function of receiving power from an external device. However, a probe antenna 70 is provided that serves to transmit pressure or temperature information from the transmitter 60 to the external device 14.
[0051]
In the embodiment of FIG. 12, as shown in FIG. 14, when the probe coil 20 is inductively coupled to the external coil 22, the probe coil 20 receives a downburst of energy 72 from the external device 14 through the external coil 22. To cause the temporary energy source 64 to charge, the downburst of energy 72 preferably lasts for a specified time, for example, about 5 seconds, but longer or shorter times can be used as desired. . This downburst of energy 72 is converted to a regulated DC voltage by rectifier 66 and regulator 68 to charge temporary energy source 64 to provide temporary energy to probe electronics 18 as described above.
[0052]
Sensor electronics 58 causes sensor 16 to sense pressure or temperature when probe coil 20 is inductively coupled to external coil 22 and probe 12 receives power from external device 14 or after temporary energy source 64 is charged. And instruct the sensor electronics 58 to communicate the sensed pressure or temperature. The sensor electronics 58 processes the sensed pressure or temperature information and passes it to the transmitter 60, where the pressure or temperature information can be transmitted from the transmitter 60 to the external device 14 by telemetry. Is converted to The pressure or temperature information is then transmitted to the external device 14 from either the transmitter 60 and the probe coil 20 or the probe antenna 70 acting as an antenna. The external device 14 receives the transmitted pressure or temperature information through an external coil 22 or an external device antenna 94 acting as an antenna and a receiver 74 preferably located on the external device 4.
[0053]
This process of sensing pressure or temperature and transmitting it to the external device 14 may be as long as the probe 12 receives power from the external device 14, or as long as the temporary energy source 64 remains powered, or shorter if desired. You can continue for hours. If the desire to sense pressure or temperature and communicate the sensed pressure or temperature occurs many times enough to exceed the power capacity of the temporary energy source 64, the power may be re-applied to the external device as described above. 14 can be downloaded. As a result, the temporary energy source 64 is recharged and the sensing and transmission process continues as described above.
[0054]
The preferred embodiment of the probe 12 is a passive system without the probe 12 having a long-term power supply. As a result, the probe 12 is a relatively low cost device for measuring and communicating pressure or temperature. This embodiment allows for "real time" snapshots of pressure or temperature.
[0055]
Alternatively, a long term power supply 76 can be provided to power the probe electronics 18 as shown in FIG. Long-term power supply 76 may take the form of a battery, such as a rechargeable or non-rechargeable battery, or a power capacitor such as a "supercapacitor," as is well understood in the art. Long term power supply 76 must have sufficient capacity to power probe 12 for a relatively long time. When using the long-term power supply 76, the temporary energy source 64 is replaced by the long-term power supply 76. As described below, if the storage device 78 is present, the long-term power source 76 can also provide power to the storage device 78.
[0056]
In the preferred embodiment (FIG. 11), external device 14 includes external coil 22, external electronics 24, power supply 26, and user communication system 28. Power supply 26 provides power to operate external electronics 24 and user communication system 28 and provides power to external coil 22, which is passed to probe 12 through inductive coupling with probe coil 20. The power supply 26 is either a battery or a normal line current adapted to provide power by means such as rectifying and filtering the AC line power to produce a DC voltage as is well understood in the art. Can be.
[0057]
External electronic circuit 24 preferably includes a receiver 74, which may be a separate component connected to external device 14. Receiver 74 receives and processes pressure or temperature information transmitted by transmitter 60 and received by external coil 22 acting as an antenna.
[0058]
The user communication system 28 is connected to the receiver 74. The user communication system 28 preferably includes a display system 80 that displays or otherwise communicates to the user the pressure or temperature information received by the receiver 74. User communication system 28 may include a display screen 82 that displays pressure or temperature information to a physician or other user. Alternatively, the user communication system 28 may communicate with the external device 14, including a personal digital assistant (PDA), via a direct connection 82 as is well understood in the art, via the Internet through telemetry 88, or through a modem. Pressure or temperature information to an external computer 84. Computer 84 can display pressure or temperature information on its display screen 82, record the information, or process the information further. If the information is passed through the Internet or through a modem, the information can be used, processed, or displayed remotely as desired.
[0059]
User communication system 28 may also include an alarm 90 that is part of external device 14 or external computer 84 that is triggered to alert the user to pressures or temperatures outside a predetermined range. The alarm 90 can also take the form of an audible or visual alarm, such as an alarm chime or a flashing visual display panel, a physical alarm, such as a vibration alarm, or other user alert or condition highlighting means as will occur to those skilled in the art.
[0060]
External device 14 also preferably includes a barometer 92. The barometer 92 measures the atmospheric pressure. This measured air pressure is then subtracted from the pressure measured by sensor 16 and transmitted from probe 12 to external device 14 to generate a "gauge" pressure. This "gauge" pressure is independent of the ambient atmospheric pressure, which is affected by the climate system and altitude. In a more preferred embodiment, external coil 22 serves both to provide power to probe 12 in combination with probe coil 20 and as an antenna to receive information transmitted by the antenna from transmitter 60. Therefore, the external coil 22 is connected to the receiver 74.
[0061]
Alternatively, there may be an external device antenna 94 separate from the external coil 22. In this embodiment, the external device antenna 94 is connected to the receiver 74 and communicates with the probe antenna 70 or the probe coil 20 to receive information transmitted from the transmitter 60. In this embodiment, the external coil 22 is not connected to the receiver 74.
[0062]
To use the device 10 to measure brain parameters such as CSF hydraulic pressure, the first step is to expose the skull and drill a hole 52 in the skull 50. The probe 12 is then implanted as described above. Thereafter, the patient's skin is closed so that the probe 12 is completely housed under the patient's skin.
[0063]
When the external device 14 is brought closer to the probe, the probe coil 20 is inductively coupled to the external coil 22, and power is transmitted from the external device 14 to the probe 12.
[0064]
Next, the hole 52 is sealed while the probe 12 is arranged at a predetermined position. Thereafter, the patient's skin is closed over the probe 12 and the wound heals. This seals the probe 12 under the patient's skin.
[0065]
When it is desired to measure a physiological parameter, the external device 14 is arranged so that the external coil 22 is located above the probe coil 20. Probe 12 is powered by transmitting a downburst of energy 72 from external device 14. In a more preferred embodiment, the first downburst of energy 72 after activation lasts about 5 seconds. This stabilizes the probe electronics 18 and allows setup such as an internal clock. The subsequent downburst of energy 72 is preferably about 2 ms long.
[0066]
In a preferred embodiment, probe 12 has no on-site battery. Thus, after activation, the probe electronics 18 performs an auto-calibration operation to ensure that physiological measurements by the sensor 16 fall within the range of the probe electronics 18. When the falling edge of the downburst of energy 72 is detected, probe 12 uplinks the detected physiological measurement to external device 14. The uplink continues as long as the external device 14 continues to send downbursts of energy 72 to the probe 12. The uplink frequency is controlled by the external device 14 and cannot exceed the rate of the energy 72 downburst. It is also possible to periodically uplink the stored calibration factors to the external device 14, or to uplink the stored calibration factors for each detected physiological parameter uplink.
[0067]
In a more preferred embodiment, each uplink of the detected physiological measurement is transmitted multiple times, eg, three times, from the probe 12 to the external device 14 to compensate for telemetry or processing errors. In continuous mode, the external device 14 intermittently sends downbursts of energy 72 to provide essentially continuous power to the probe 12 and receives uplink physiological parameter measurements.
[0068]
In addition, the calibration coefficients of sensor 16 may be stored in probe 12, probe electronics 18, storage device 78, or microprocessor 102, as described above. If these calibration coefficients are stored in the probe 12, these coefficients are transferred from the probe 12 to an external device for post-measurement processing in order to achieve accurate reporting of the physiological parameters measured by the sensor 16. Can be uplinked. These coefficients may be uplinked to the external device 14 when the probe 12 is first activated, or may be uplinked for each uplink of a sensed physiological parameter.
[0069]
In addition, data such as the serial number or model number of the probe 12 can be stored in the probe electronics 18, storage 78 or microprocessor 102 or external device 14. If such a serial number or model number is stored in the probe 12, this information can be uplinked to the external device 14 when the probe is first activated, or the uplink of the sensed physiological parameter. Uplink can be performed every time.
[0070]
In a preferred embodiment, external device 14 is a single unit that includes components of external coil 22, external electronics 24, power supply 26, user communication system 28 and external device antenna, if present. However, the external device 14 can be two or more separation devices. For example, as shown in FIG. 16, one device 96 may provide power to the probe 12 through an inductive coupling between the probe coil 20 and the external coil 22 and a second device 98 may be transmitted by the transmitter 60. And the third device 100 can display the pressure or temperature information received by the second device 98.
[0071]
In a preferred embodiment where the probe 12 includes a passive system 24, the probe coil 20 and the external coil 22 can be combined to pass power from the external coil 14 to the probe 12 and to transfer pressure or temperature information from the probe 12 to the external device 14 It is important to be able to pass to. It may be desirable to audibly confirm that the probe coil 20 and the external coil 22 are coupled. This can be achieved by the probe 12 uploading a signal to the external device 14 indicating that the probe coil 20 and the external coil 22 are inductively coupled. This signal can be used by external device 14 to trigger an audible signal indicating that probe 12 and external device 14 are inductively coupled.
[0072]
Alternatively, the load on external coil 22 caused by inductive coupling with probe coil 20 can be detected by external device 14 and used to determine coupling efficiency. This load can be detected by monitoring the power passed through the external coil 22. As the inductive coupling between the external coil and the probe coil 20 increases, the power passing through the external coil 22 to the probe coil 20 increases. By monitoring this power and comparing it to the instantaneous power measure, the trend of transmission (ie, increase or decrease) or the relative maximum transmission can be determined. Using this information, it can be determined whether the efficiency of the coupling between the external coil 22 and the probe coil 20 has been increased or reached the optimal coupling position.
[0073]
Further, it may be desirable to store the pressure or temperature information sensed from sensor 16 for later transmission from transmitter 60. This can be accomplished by attaching storage 78 to sensor 16 and transmitter 60 (FIG. 17). The storage device 78 is disclosed in "Compressed Patient Narrative Storage In and Full Text Reconstruction from Implantable Medical, United States Patent No. 5, U.S. Pat. No. 5,963, issued to William F. Kemmerler on October 6, 1998; US Pat. No. 5,549,654 entitled "Interactive Interpretation of Event Markers in Body-Implantable Medical Devices," issued to Richard M. Powell on Aug. 27, 2014. Both are assigned to the assignee of the present application, and reference is made to the entire teachings thereof. Incorporated into this.
[0074]
The storage device 78 can be located on the probe head 36, the electronics case 41 or the body 48, or can be located away from the probe 12 but electrically connected. For example, the storage device 78 can be placed near the collarbone in a manner similar to the placement of the Reveal® cardiac recording device manufactured and sold by Medtronic, Inc. of Minneapolis, MN. Further, the storage device 78 may be connected directly to the probe 12 by wire, through the "body bus" communication system described above, or through other similar communication means.
[0075]
In this embodiment, probe 12 requires a long-term power supply 76 to provide power to sensor 16, sensor electronics 58, and storage 78. Sensor electronics 58 periodically instructs sensor 16 to sense pressure or temperature. Alternatively, sensor electronics 58 can receive an indication from a signal from external device 14 that instructs sensor 16 to sense pressure or temperature information.
[0076]
In each case, the sensed pressure or temperature is then communicated to a storage device and stored there. The pressure or temperature information is then uploaded from the storage device 78 to the external device 14 via the transmitter 60 as described above, either periodically or when queried from the external device 14.
[0077]
In another embodiment (FIG. 18), sensor electronics 28 and storage 78 can be connected to microprocessor 102 as shown in FIG. In this embodiment, the pressure or temperature measurements can be processed by the microprocessor 102 before being stored in the storage device 78. Alternatively, microprocessor 102 may retrieve a series of stored measurements from storage device 78 and process it, for example, to provide a continuous average pressure or temperature. Such processed information can be transmitted from the probe 12 to the external device 14 during processing, or can be stored in the storage device 78 and transmitted to the external device 14 at a later time.
[0078]
The sensed pressure or temperature information can also be used to control a CSF shunt drainage system as described above. In this embodiment, shown schematically in FIG. 18, the sensed pressure or temperature information is used to activate the controller 104, if desired.
[0079]
In the embodiment of FIG. 18, the drainage catheter 2 is located in the ventricle 4 of the patient and is coupled to the controller 104. Preferably, the controller 104 connects to a peritoneal or atrial catheter 8, but the controller 104 can also connect to a drainage bag. The control device 104 can be a pump or valve connected between the drainage catheter 2 and the peritoneal or atrial catheter 8 or drainage bag. If the controller 104 is a pump, the pump pumps CSF fluid from the ventricle 4 into the peritoneal or atrial catheter 8, where it is absorbed into the body or into a drainage bag. If the controller 104 is a valve, the valve allows the CSF fluid to drain from the ventricle 4 through the peritoneal cavity or atrial catheter 8 or into the drainage bag when open.
[0080]
In the illustrated embodiment, the controller 104 connects to the microprocessor 102 so that the microprocessor 102 controls whether the pump pumps CSF fluid or opens a valve to allow drainage of the CSF fluid. Is done.
[0081]
In use, when the microprocessor 102 determines that the CSF pressure sensed by the sensor 16 exceeds a predetermined level, the microprocessor 102 activates the controller 104 to pump CSF fluid or to operate a valve. To release excess CSF fluid from the patient's ventricle. When the microprocessor 102 determines that the CSF pressure has dropped to an acceptable level, the microprocessor 102 causes the controller 104 to stop pumping CSF fluid or stop the CSF from draining through the valve. Let the valve close.
[0082]
The controller 104 can also control the operation of the adjustable subcutaneous implantable fluid flow valve of the CSF shunt system. Such a device is manufactured and sold by Medtronic-PS Medical of Goltar, California, and is published on June 10, 1997 by William J. Bertland and David A. Watson in "Implantable Adjustable Fluid Flow." No. 5,637,083, entitled "Control Valve", a Strata (R) valve adjustable valve. Such an adjustable valve is useful in a physiological shunt system to control the flow of fluid from one part of the body to another, such as from the patient's ventricle to the patient's peritoneal cavity or atrium. It is. The controller 104 controls the movement of a magnetic field applied externally or percutaneously, for example, to cause the valve to achieve various pressure or flow characteristics.
[0083]
In a variation of the embodiment where the controller 104 is used to control a valve or pump, the controller may also control another medical device, such as a pacer, a neurological stimulator or a drag pump. In these medical devices, or in the CSF shunt drainage system described above, in addition to activating the controller 104 when the parameter of interest exceeds a specified range, the controller 104 It can be activated whenever the value falls outside the predetermined range, and stopped when the parameter falls within the predetermined range. In addition, the controller 104 does not simply respond dichotomously to the sensed parameter of interest, but rather the controller 104 may be proportional, formula, logarithmic, geometric, exponential, or a predetermined response. The sensed parameters can be responded to in a manner, or inversely to any of these responses. In this embodiment, a value representing the sensed parameter itself may be used to determine the response of controller 104.
[0084]
In use, the sensor 16 is preferably located in or in contact with the parenchyma or ventricle capable of sensing pressure or temperature information. Alternatively, the sensor 16 may be a spinal column, for example, a body organ, such as a liver, kidney, heart, bladder, tumor or tumor, body tissue, joint, fossa, sinus or organ or to name a few other organs that will occur to those skilled in the art. It can be placed in the space between the tissues or in contact with them.
[0085]
In a more preferred embodiment, probe 12 has either a pressure or temperature sensor 16. However, probe 12 may have both a pressure and temperature sensor 16. Further, while the sensor 16 has been described as a sensor that senses pressure or temperature, the sensor 16 can be used to provide oxygen partial pressure (PO ₂ ), Mixed venous oxygen saturation (SVO) ₂ ), And a sensor for detecting blood sugar and pH. If sensor 16 senses a parameter other than pressure or temperature, the probe may include such a sensor in addition to, or in any combination with, sensors that sense pressure or temperature. As a result, the sensor 16 can detect two or more parameters sequentially or simultaneously.
[0086]
In addition, in the preferred embodiment, probe electronics 18 is located within electronics case 42. In alternative embodiments, the probe electronics 18 can be located in the body 48 or in the probe head 36.
[0087]
One advantage of the device 10 described herein is that the organ or tissue of interest, for example, the brain, is only exposed once during transplantation, thus simplifying long-term monitoring of physiological parameters without the risk of infection. Is what you can do. Thereafter, the probe 12 is housed in the patient's skin, where it can measure and transmit a physiological parameter of interest.
[0088]
In the form of a pressure sensor, a further advantage of the present invention over a conventional pressure sensor is that the pressure sensor is placed directly in the brain without attaching a tube to the outside world. Further, the preferred embodiment device does not have an on-site battery. Therefore, probe 12 must perform a startup sequence each time power is applied to probe 12. In the present invention, this startup sequence involves the execution of an auto-calibration algorithm. This self-calibration algorithm ensures that the pressure measurements received from sensor 16 are always within the desired range of probe electronics 18.
[0089]
In an alternative embodiment (FIG. 19), the probe 12, external device 14, drainage catheter 2, atrial catheter 8 and controller 104 are as described above in connection with the embodiment of FIG. 18, with the following exceptions. . In this embodiment, the control device 104 is controlled by the external device 14 so that the external device 14 determines whether the pump pumps CSF fluid or opens a valve to allow drainage of the CSF fluid. Control. In this embodiment, the external device has a microprocessor 102 ′, similar to the microprocessor 102, for processing physiological parameter information sensed by the sensor 16, and the controller 104 communicates with the external device via the external coil 22. It has an antenna 20 ′ similar to the probe coil 20 for receiving control signals from 14. In either embodiment of FIG. 18 or FIG. 19, the sensor 16 can be located remotely from the probe 12.
[0090]
In use, sensor 16 senses pressure as described above. This pressure information can be processed by the microprocessor 102 on the probe 12, or can be passed to the external device 14 entirely from the probe 12 or after partial or complete processing by the microprocessor 102. The external device 14 then determines, via the microprocessor 102 ', whether the CSF pressure detected by the sensor 16 exceeds a predetermined level. When the CSF pressure exceeds a predetermined level, external device 12 activates controller 104 to pump CSF fluid or open a valve to drain excess CSF fluid from the patient's ventricle. When the external device 12 determines that the CSF pressure has dropped to an acceptable level, the external device 12 causes the controller 104 to stop pumping CSF fluid or stop the CSF from draining through the valve. Let the valve close.
[0091]
In a further alternative embodiment (FIG. 20), the external device 14, drainage catheter 2, atrial catheter 8 and controller 104 are as described above in connection with the embodiments of FIGS. 18 and 19, with the following exceptions. . In this embodiment, the electronics of probe 12 are coupled to controller 104. Preferably, the sensor 16 is located away from the probe 12, but it is not essential. The controller 104 can be controlled by either the microprocessor 102, the microprocessor 102 'or a combination of the microprocessors 102 and 102' as described above.
[0092]
Particular systems and devices have been described above and illustrated in the figures. The invention also includes, in one embodiment, a method of measuring and communicating parameters of a brain, tissue or other organ. Referring to FIG. 21, the method includes providing 106 a sensor 16 for sensing a parameter of interest, and at or near a target of a brain, tissue, or other organ capable of sensing the parameter of interest. Implanting the sensor 16; providing a reactor capable of displaying, processing, or taking action on the parameters; 110, sensing the parameter of interest; and 112 detecting the parameter of interest. Communicating the parameters to display or process the parameters or to take action in response to the parameters 114.
[0093]
A specific embodiment of the invention described above is shown in FIG. In this embodiment, a method for controlling a CSF shunt drainage system is disclosed. The method includes providing 116 a probe having a sensor that senses a parameter of interest, and a CSF shunt that includes a controller 104 to affect the flow of CSF fluid from the patient's ventricle to the CSF shunt drainage system. Providing a drainage system 118; implanting a probe 120 such that the sensor is placed in the patient's ventricle; sensing 122 the patient's CSF fluid pressure; and controlling in response to the sensed parameters. Activating the device 104.
[0094]
A further embodiment of the method of the present invention shown in FIG. 23 illustrates a method for controlling a medical device in response to a sensed parameter. The method includes providing 126 a probe having a sensor that senses a parameter of interest, and a medical device having a controller 104 that operates in response to the sensed parameter of interest to control operation of the medical device. , Implanting the probe so that the sensor is located at the desired location on the patient, sensing 132 a parameter of interest, and controlling the controller 104 in response to the sensed parameter. Activating 134.
[0095]
Providing a sensor 16 for sensing a parameter of interest or providing a probe having a sensor for sensing a parameter of interest 116, 126 includes providing the sensor 16 described and illustrated above. However, while the sensor 16 has been described primarily here as a sensor that senses pressure or temperature, the sensor 16 can be used to provide oxygen partial pressure (PO ₂ ), Mixed venous oxygen saturation (SVO) ₂ ), Obviously it could be a sensor to detect blood sugar and pH. Further, the sensor 16 can detect two or more parameters sequentially or simultaneously. Further, although the sensor 16 is described as being mainly part of the probe 12 in one embodiment, the sensor 16 need not be part of the probe 12.
[0096]
Implanting the sensor 108 in or near the target of the brain, tissue or other organ capable of sensing the parameter of interest, or implanting the probe so that the sensor is located at the desired location in the patient Steps 120, 130 pierce the skin and tissue or bone if necessary, place the sensor 16 at the desired location in the brain, tissue or other organ, secure the sensor if necessary, and Surgically closing the skin so that it is contained under the patient's skin.
[0097]
The step 110 of providing a reactor capable of displaying, processing or taking action on parameters may alternatively provide an external device 14 or provide the probe 12 itself, as described and illustrated above. Providing the microprocessor 102 to the computer. Activating the controller 104 in response to the sensed parameters 124, 134 activates the controller 104 via the external device 14 or the controller 104. In either case, the external device 14 or the microprocessor 102 may process the parameter or cause an action to be taken in response to the parameter, and in the case of the external device 14, display the parameter data. Furthermore, while the present invention has been described primarily as having the microprocessor 104 in the probe 12 itself, the microprocessor 104 can be provided in the external device 14, the medical device being actuated, or the external device 14 (if present), the probe. 12 or a separate medical device.
[0098]
Displaying or processing the parameter or causing an action to be taken in response to the parameter 112 includes displaying or processing the parameter or causing an action to be taken in response to the parameter as described above.
[0099]
The description contained herein is intended as an illustration of the invention and is not an exhaustive description. Many variations, combinations, and alternatives of the disclosed embodiments will occur to those skilled in the art. Furthermore, although specific values have been given, these values are intended as illustrative of the present invention and are not intended to be limiting. These alternatives, combinations and variations are intended to be included within the scope of the claims. Those skilled in the art may recognize other equivalents in the specific embodiments described herein, and such equivalents are also intended to be included in the claims.
[Brief description of the drawings]
FIG.
FIG. 1 is a schematic diagram of a CSF shunt drainage system.
FIG. 2
FIG. 2 is a block diagram of the present invention.
FIG. 3
FIG. 3 is a side view of a more preferred embodiment of the present invention.
FIG. 4
FIG. 4 is a side sectional view of the embodiment of FIG.
FIG. 5
FIG. 5 is a side cross-sectional view of the embodiment of FIG. 3 positioned within the skull.
FIG. 6
FIG. 6 is a side cross-sectional view of another embodiment of the present invention located in the skull.
FIG. 7
FIG. 7 is a side cross-sectional view of another embodiment of the present invention located on the skull.
FIG. 8
FIG. 8 is a perspective view of another embodiment of the present invention.
FIG. 9
FIG. 9 is a perspective view of another embodiment of the present invention.
FIG. 10
FIG. 10 is a side sectional view of another embodiment of the present invention.
FIG. 11
FIG. 11 is a schematic diagram of a more preferred embodiment of the present invention.
FIG.
FIG. 12 is a schematic diagram of another embodiment of the present invention.
FIG. 13
FIG. 13 is a schematic diagram of another embodiment of the present invention.
FIG. 14
FIG. 14 is a diagram showing a charging and transmission sequence according to one embodiment of the present invention.
FIG.
FIG. 15 is a schematic diagram of another embodiment of the present invention.
FIG.
FIG. 16 is a block diagram according to another embodiment of the present invention.
FIG.
FIG. 17 is a schematic diagram of another embodiment of the present invention.
FIG.
FIG. 18 is a schematic view of another embodiment of the present invention.
FIG.
FIG. 19 is a schematic diagram of another embodiment of the present invention.
FIG.
FIG. 20 is a schematic view of another embodiment of the present invention.
FIG. 21
FIG. 21 is a flowchart showing one embodiment of the method of the present invention.
FIG.
FIG. 22 is a flowchart showing another embodiment of the method of the present invention.
FIG. 23
FIG. 23 is a flowchart showing another embodiment of the method of the present invention.

Claims (26)

An apparatus for measuring and communicating parameters of a brain, tissue or other organ, comprising:
A sensor for detecting the parameter of interest;
An external device that can display, process, or take action on the parameters;
A communication system that communicates the detected parameter from the sensor to the external device,
Equipment including. Said sensor, a pressure sensor, a temperature sensor, an oxygen partial pressure (PO ₂₎ sensor, mixed venous blood oxygen saturation (SVO ₂₎ sensor, is selected from the group consisting of blood glucose sensor and pH sensor according to claim 1 The described device. The apparatus of claim 1, further comprising a probe having a distal end, wherein the probe includes the sensor, wherein the sensor is located at the distal end of the probe. 4. The apparatus of claim 3, wherein said probe has a long-term energy source for powering itself and said sensor. The device of claim 4, wherein the long-term energy source is rechargeable. The device of claim 4, wherein the long-term energy source is a battery. The apparatus of claim 4, wherein said long-term energy source is a capacitor. The apparatus of claim 4, wherein the sensor is electrically connected to the probe via a body bus. The apparatus of claim 4, wherein said probe comprises a microprocessor. The apparatus according to claim 4, wherein the probe has a storage system for storing detected parameter information. 11. The apparatus of claim 10, wherein a calibration factor unique to each sensor is stored in the storage device for post-measurement processing purposes to achieve accurate reporting of physiological parameters measured by the sensors. The apparatus of claim 4, wherein said probe comprises an implanted probe coil. The apparatus according to claim 12, wherein the probe coil is an induction coil. The apparatus of claim 4, wherein the sensor is separate from the probe. The apparatus of claim 4, further comprising a bar hole ring having an opening, wherein the probe is disposed within the opening of the bar hole ring. The apparatus of claim 1, further comprising a passive power system that powers the sensor to enable parameter information to be detected by the sensor. The communication system includes a part associated with and connected to the sensor, and associated with and connected to the sensor of the communication system to communicate parameter information detected by the sensor to the external device. The apparatus of claim 1, further comprising a passive power system for powering the portion. A CSF shunt having a catheter positioned in the ventricle, a shunt used as a conduit to transfer CSF from one location in the body to another, and a pump positioned between the catheter and the shunt The apparatus of claim 1, further comprising a drainage system, wherein the pump operates in response to a parameter of interest sensed by the sensor. A CSF shunt having a catheter positioned in the ventricle, a shunt used as a conduit to transfer CSF from one location in the body to another, and a pump positioned between the catheter and the shunt The apparatus of claim 1, further comprising a drainage system, wherein the pump operates in response to a parameter of interest sensed by the sensor. The apparatus of claim 1, wherein a calibration factor unique to each sensor is stored in the external device for post-measurement processing purposes to achieve accurate reporting of physiological parameters measured by the sensors. The apparatus of claim 1, wherein a calibration factor unique to each sensor is stored in the sensor for post-measurement processing purposes to achieve accurate reporting of physiological parameters measured by the sensor. The apparatus of claim 1, wherein the communication system includes a display system that displays the sensed parameter information or otherwise communicates to a user. The device of claim 1, wherein the external device includes a barometer that measures atmospheric pressure. A method for measuring brain parameters such as CSF hydraulic pressure,
Providing a probe having a sensor for sensing the parameter of interest;
Providing an external device capable of displaying, processing, or taking action on the parameters;
Providing a communication system that communicates the detected parameter from the probe to the external device,
Exposing the patient's skull;
Drilling a hole in the skull;
Implanting the probe such that the sensor is positioned within the skull;
Closing the patient's skin so that the probe is completely contained under the patient's skin;
Bringing the external device closer to the probe such that the sensed parameters are transmitted from the probe to the external device. A method of controlling a CSF shunt drainage system, comprising:
Providing a probe having a sensor for sensing a parameter of interest;
Providing a CSF shunt drainage system that includes a controller that affects the flow of CSF fluid from the patient's ventricle to the CSF shunt drainage system;
Implanting the probe such that the sensor is placed in the patient's ventricle;
Detecting the CSF fluid pressure of the patient;
Activating the controller in response to the sensed parameter. A method of controlling a medical device in response to a detected parameter,
Providing a probe having a sensor for sensing a parameter of interest;
Providing a medical device having a controller operative in response to the sensed parameter of interest to control operation of the medical device;
Implanting the probe such that the sensor is located at a desired location within the patient;
Detecting the parameter of interest;
Activating the controller in response to the sensed parameter.

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