Sensor device for detecting intracranial pressure and method for detecting intracranial pressure

Abstract

The present disclosure relates to a sensor device (2) for detecting intracranial pressure, said sensor device (2) comprising a housing (8) defining an interior space (15a; 15b) configured to accommodate a pressure sensing device (9) and an electronic control unit (14) to which said pressure sensing device (9) is connected; and fixation means (7; 2b) cooperating with said housing (8) for mounting said sensor device (2) within a human skull (3), optionally in a permanent manner. Furthermore, said housing (8) has an opening (11) covered by a membrane (12) made of titanium or a similar thin, flexible material, and is configured to generate vibrations in accordance with existing external pressure, said vibrations being transmitted to said pressure sensing device (9). The present invention also relates to a method for detecting intracranial pressure.

Description

[Technical Field]

[0001] The present invention relates to a sensor device for detecting intracranial pressure, the sensor device comprising a housing defining an interior space configured to accommodate a pressure sensing device and an electronic control unit to which the pressure sensing device is connected, and fixation means cooperating with the housing for mounting the sensor device within a human skull, optionally in a permanent manner.

[0002] The present disclosure also relates to a method for detecting intracranial pressure by means of a sensor device, the method comprising providing an interior space by means of a housing forming part of the sensor device, accommodating within the interior space a pressure sensing device and an electronic control unit to which the pressure sensing device is connected, and attaching, optionally permanently, the sensor device to a human skull by fixation means cooperating with the housing. [Background technology]

[0003] There is a need in the medical field for devices and methods for measuring intracranial pressure in a human brain and detecting brain pulsations. Such a need can arise as a result of certain neurological disorders and injuries to the brain, such as hydrocephalus. This condition corresponds to an abnormal accumulation of fluid in cavities within the brain and can generally be treated by surgically inserting a drainage system to control the flow of fluid within the brain.

[0004] Additionally, it is known in the art to provide a pressure monitoring system for detecting and monitoring intracranial pressure. Such a system may be implemented in the patient's head and used in conjunction with the drainage system described above when treating hydrocephalus.

[0005] Based on the above, there consequently exists a need for systems and methods for reliably and accurately measuring and monitoring intracranial pressure during certain conditions, such as hydrocephalus.

[0006] Referring to the prior art, it will be noted that patent document US11422051 teaches a device for sensing the pressure of a shunt for use in the treatment of hydrocephalus. The device is based on a pressure sensor located in a cavity in a housing. The housing also has an inlet and an outlet, which are used as part of a hydrocephalus shunt.

[0007] Furthermore, patent document US2012 / 0265028 teaches a sensor device based on a circular housing having a bottom wall configured as a diaphragm that is affected by pressure in the brain.

[0008] Although the devices according to the two aforementioned patents are suitable for measuring pressure during hydrocephalus treatment, there is a need for further improvements in such systems.

[0009] A particular problem that can occur with pressure sensing systems of the type described above relates to zero drift (i.e., the tendency of the sensor's zero reading to drift and fluctuate even though the input signal is zero). Such a condition can occur over time and as a result of the environmental conditions in which the sensor operates. As a result, the measurement data may not be sufficiently accurate.

[0010] Furthermore, the environment in which sensor devices of the above type are worn and used (i.e., inside the human brain) is harsh: for example, there is a risk that bodily fluids may leak into the sensor device, which may lead to a deterioration in the quality of the measurements and a shortened lifespan of the sensor device.

[0011] For the reasons stated above, there exists a need for improved and optimal devices and methods for measuring and monitoring intracranial pressure, for example, in connection with hydrocephalus. Summary of the Invention

[0012] SUMMARY OF THE DISCLOSURE In accordance with the present disclosure, an improved sensor device and corresponding method is provided that overcomes the shortcomings of known devices within the art.

[0013] For this reason, according to the present disclosure, there is provided a sensor device for detecting intracranial pressure, said sensor device comprising: a housing defining an interior space configured to accommodate a pressure sensing device and an electronic control unit to which said pressure sensing device is connected; and fixation means cooperating with said housing for mounting said sensor device, optionally in a permanent manner, within a human skull. Further, the housing has an opening covered by a membrane made of titanium or a similar thin, flexible material, and is configured to generate vibrations in accordance with an existing external pressure, said vibrations being transmitted to said pressure sensing device.

[0014] Certain advantages are achieved by the device according to the present disclosure. In particular, due to the above-mentioned features, the titanium membrane can be configured to vibrate freely without any friction and transmit its movement (i.e., movement usually in the form of deflection) to the pressure sensing device, which then indicates accurate measurement data. Furthermore, the above-mentioned device is based on the use of a compact electronic unit with short electrical connections and a low risk for zero drift, which also contributes to accurate measurements. Furthermore, the sensor device can be configured as a sealed unit.

[0015] According to one embodiment, the housing and the opening are formed to have a generally circular cross section, and the membrane has a circular shape corresponding to the opening.

[0016] According to one embodiment, the membrane has a thickness of less than 100 μm.

[0017] According to one embodiment, the membrane has a thickness ranging from 5 to 50 μm.

[0018] According to one embodiment, the sensor device further includes a battery disposed within the interior space.

[0019] According to one embodiment, the sensor device further comprises a charging device configured for contactless charging of the storage battery.

[0020] According to one embodiment, the sensor device further comprises a charging device based on a device for energy harvesting.

[0021] According to one embodiment, the accumulator is based on a capacitor circuit.

[0022] According to one embodiment, the housing is made of titanium.

[0023] According to one embodiment, the pressure sensing device is mounted on a circuit board, the circuit board being configured to divide the interior space into a first subspace between the circuit board and the membrane and a second subspace between the circuit board and an end portion of the housing.

[0024] According to one embodiment, the first subspace is filled with an incompressible medium, a gas or a vacuum.

[0025] According to one embodiment, the incompressible medium comprises at least one of a liquid, an oil, or a gel / silicone.

[0026] According to one embodiment, the pressure sensing device is mounted on the circuit board on the side facing the membrane.

[0027] According to one embodiment, the electronic control unit is connected to a gyro.

[0028] According to one embodiment, the electronic control unit is configured to calibrate the measurements of the pressure sensing device based on the prevailing atmospheric pressure.

[0029] According to one embodiment, the housing is formed with an area that is open to allow wireless signal transmission.

[0030] According to one embodiment, the open area is covered with a sealing material such as ceramic, glass, epoxy material, silicone, or the like.

[0031] The present disclosure also relates to a method for detecting intracranial pressure.

[0032] Further advantages and advantageous features of the presently contemplated embodiments are disclosed in the following description and dependent claims. [Brief explanation of the drawings]

[0033] The present disclosure will be described in more detail below with reference to the figures shown in the accompanying drawings.

[0034] [Figure 1] FIG. 1 is a cross-sectional view of a portion of a human brain, onto which a sensor device according to a first embodiment of the present invention is attached.

[0035] [Figure 2] FIG. 2 shows a cross-sectional view of the sensor device according to the first embodiment.

[0036] [Figure 3] FIG. 3 shows a further cross-sectional view of the sensor device.

[0037] [Figure 4] FIG. 4 shows a schematic cross-sectional view of the sensor device corresponding to the cross-sectional view of FIG.

[0038] [Figure 5] FIG. 5 shows details of the sensor device according to the improved embodiment.

[0039] [Figure 6] FIG. 6 shows a further schematic diagram corresponding to FIG. DETAILED DESCRIPTION OF THE INVENTION

[0040] Various aspects of the present disclosure will be described in more detail below with reference to the accompanying drawings and specific embodiments. This disclosure may be embodied in many different forms and should not be construed as limited to the following embodiments.

[0041] 1, there is shown a cross-sectional view of an area of ​​a human head 1, onto which a sensor device 2 according to one embodiment of the present invention is mounted. Certain parts of the head 1 are shown, such as the skull 3, the actual brain 4 with its cerebral cortex, and the dura mater 5 (i.e., the dura mater surrounding the brain 4).

[0042] As mentioned above, the sensor device 2 is configured to be attached in a permanent or non-permanent manner to the skull 3. Preferably, the sensor device 2 is attached by first creating a hole 6 in the skull 3 such that the inner dimensions of the hole 6 approximately correspond to the outer dimensions of the sensor device 2.

[0043] As will be described in more detail below, the sensor device 2 is configured with a lower end portion 2a facing towards the brain 4 and an upper end portion 2b formed as a flange or rim with holes associated with screws 7 or similar fixation elements. The number of screws 7 or similar fixation elements corresponds to the number of holes. In this way, a fixation device is defined for mounting the sensor device 2 in the intended position as shown in Figure 1. More precisely, the sensor device 2 can be mounted (if desired in a substantially permanent manner) on the skull 3.

[0044] 2 and 3, there is shown in more detail how the sensor device 2 is constructed. According to one embodiment, the sensor device 2 is based on a generally cylindrical housing 8, preferably made from titanium. The housing 8 is hermetically sealed, meaning that there is no leakage into the housing 8 from the outside, e.g., by fluids in the brain 4. The housing 8 preferably has a wall thickness of 100 to 2000 μm. Also, according to one aspect, the diameter of the housing 8 is preferably 5 to 15 mm.

[0045] The housing 8 is connected to the upper end portion 2b of the sensor device 2 (i.e., the flange described above formed by the upper end portion 2b and used to fix the housing 8 and thereby the entire sensor device 2 in the correct position as shown in Figure 1).

[0046] Housing 8 is also connected to lower end portion 2a of sensor device 2 and is configured to house therein a pressure sensing device 9. Pressure sensing device 9 is positioned to face towards brain 4 (during operation of sensor device 2) for measuring intracranial pressure within brain 4 in a manner described in more detail below.

[0047] The lower end portion 2a is preferably formed with a substantially circular end wall 10 formed with a circular opening 11 over which a membrane 12 is attached to cover the opening 11. According to one embodiment, the membrane 12 is substantially circular and made from a thin, flexible material. Preferably, the membrane 12 is made from titanium and has a diameter preferably in the range of 4-8 mm, which corresponds approximately to the diameter of the opening 11.

[0048] The role of the membrane 12 is to be affected by the pulsations and intracranial pressure in the brain 4, such that the movement of the membrane due to the fluctuating pressure in the brain 4 (e.g. in the form of regular or irregular flexures or vibrations) is transmitted towards the pressure sensing device 9 located inside the housing 8. In this way, pressure measurements can be indicated in an accurate manner by the pressure sensing device 9.

[0049] According to one embodiment, the pressure sensing device 9 is mounted on an electrical circuit such as a printed circuit board 13, which is located on the opposite side of the pressure sensing device 9, i.e., the side of the pressure sensing device 9 that does not face towards the brain 4. The circuit board 13 is also configured to support an electronic control unit 14 to which the pressure sensing device 9 is electrically connected.

[0050] The electronic control unit 14 is programmed to control the measurement process regarding intracranial pressure and to store and transmit the measurement data provided by the pressure sensing device 9. For this purpose, according to one embodiment, the electronic control unit 14 is based on a microprocessor unit associated with a memory unit (for storing the measurement data), an input unit (for allowing the input of the measurement data), and an output unit (for transmitting the measurement data to an external component). The detailed implementation of the electronic control unit 14 is such that it is constructed according to known techniques. For this reason, it will not be further detailed here.

[0051] 2, the housing 8 defines, encloses, and seals an internal cavity or space 15, which is divided into a lower internal space 15a and an upper internal space 15b. The lower internal space 15a and the upper internal space 15b are separated by an electrical circuit board 13, which in turn functions as a dividing wall. This also means that the pressure sensing device 9 is located within the lower internal space 15a. Preferably, the lower internal space 15a and the upper internal space 15b are sealed, i.e., not connected, to each other.

[0052] According to one embodiment, the lower interior space 15a is filled with an incompressible medium, such as preferably air, oil or silicone (in the form of a gel). When electronic components (such as the pressure sensing device 9) are enclosed in a hermetically sealed enclosure, they may experience pressure differences at levels different from mean sea level. This may cause deformation of the thin membrane 12, which may lead to undesirable zero drift and possibly damage to the membrane 12 due to such pressure differences. By filling the lower interior space 15a with an incompressible medium, compensation for such pressure differences may be provided.

[0053] 2, printed circuit board 13 is connected to a power source 16, preferably in the form of a storage battery such as a rechargeable battery, for powering the various components (i.e., electronic control unit 14 and its associated components) located on printed circuit board 13. As shown in FIG. 2, power source 16 is located in upper interior space 15b, i.e., on the same side of circuit board 13 as electronic control unit 14.

[0054] The power source 16 is further connected to a charging device 17, which is preferably located in the upper interior space 15b. According to one embodiment, the charging device 17 is of the energy harvesting type. Alternatively, the charging device 17 can be based on a capacitor circuit with an induction coil configured for contactless charging (i.e. wireless charging) via an external charging unit (not shown).

[0055] FIG. 3 describes an embodiment having an energy source 16 and a coil or energy harvester 17 .

[0056] FIG. 4 is a schematic diagram of a sensor device substantially corresponding to FIGS.

[0057] 5 and 6 show a further exemplary embodiment of how the sensor device can be mounted. This embodiment is slightly modified compared to FIGS. 1 to 4. More precisely, the control unit 14a (which corresponds roughly to the control unit 14 described above) can be provided with one or more pins 22. These pins 22 are arranged to align and cooperate with corresponding holes 23 (see especially FIG. 6) in the power source 16a. In this way, the control unit 14a and the power source 16a can be mounted together with precision. Further referring to FIGS. 5 and 6, the power source 16a also includes specific electronic modules such as a central processing unit 18, a gyro sensor 19, an A / D converter 20, and an AC / DC converter 21. The central processing unit 18 can be arranged to operate together with the control unit 14a in any suitable manner. That is, one of these units can be a memory unit, while the other can include a microprocessor, communication components, and the like, or vice versa.

[0058] The electronic control unit 14 also includes an electrical connection (not shown) to a power source 16a. Figure 5 also shows a pressure sensing device 9 (not shown in Figure 6). The control unit 14a and power source 16a shown in Figures 5 and 6 are preferably generally circular and correspond approximately to the internal dimensions of the housing 8. The gyro sensor 19 is known per se and is used to provide information about the position of the user's head in three-dimensional space when the sensor device is implanted in the head.

[0059] According to one embodiment not shown, a portion of the upper end portion 2b is open to allow wireless transmission into and out of the housing 8. The opening is preferably sealed with a ceramic material, or alternatively with epoxy or silicone, to facilitate transmission of wireless signals to and from the sensor device while ensuring a tight seal of the housing 8. This is also done to allow contactless charging of the accumulator 16, for example, as shown in FIG.

[0060] 1-5, the present disclosure relates to a sensor device for detecting intracranial pressure. Sensor device 2 includes a housing 8 defining an interior space configured to accommodate a pressure sensing device 9 and an electronic control unit 14 to which said pressure sensing device 9 is connected. Sensor device 2 also includes fixation means (i.e., screws 7 associated with corresponding holes in flange 2b) that cooperate with said housing 8 to attach said sensor device 2, optionally permanently, to a human skull 3.

[0061] Furthermore, the housing 8 is formed with an opening 11, which is covered by a membrane 12 made of titanium and configured to generate vibrations according to the existing external pressure, said vibrations being transmitted to the pressure sensing device 9. Furthermore, the pressure sensing device 9 is mounted on the underside of the circuit board 13, which leads to certain advantages. Firstly, it should be mentioned that the pressure sensing device 9 provides extremely accurate and highly precise measurements with virtually no risk of zero drift. As shown in the embodiment of Figures 2 to 4, the housing 8 is preferably tapered along the area of ​​the housing 8, which preferably terminates at the opening 11 and the membrane 12.

[0062] According to one embodiment, the pressure sensing device 9 is located entirely within the internal space (see FIG. 2 ), which is formed by the housing 8 and the membrane 12, with the membrane 12 covering the opening 11 and in this way forming a sealed housing that prevents the passage of any liquid or gas. Preferably, the housing 8 is manufactured in one piece or as a single unit. The pressure sensing device 9 does not form part of the actual housing or enclosure of the internal space, but is located entirely within the boundary defined by the housing 8 and the membrane 12, i.e., inside the housing 8. This also means that the membrane 12 and the pressure sensing device 9 are two separate components. Furthermore, the membrane 12 is configured to transmit vibrations from outside the housing 8 (which cause the membrane 12 to move) to the pressure sensing device 9 via a compressible or incompressible medium. Preferably, the medium is constituted by a gas.

[0063] Furthermore, according to one embodiment, the pressure sensing device 9 is preferably an active capacitor sensor device. The pressure sensing device 9 is controlled by an integrated electrical circuit 14 to which it is connected, and is further powered by an integrated energy source 16 (see FIG. 3).

[0064] 2, the housing 8 and the opening 11 are formed to have a substantially circular cross section, and the membrane 12 has a circular shape corresponding to the opening 11. The membrane 12 has a thickness of less than 100 μm. According to one embodiment, the membrane 12 has a thickness in the range of 5 to 50 μm.

[0065] The actual measurements and geometry of the sensor device 2 (i.e., with regard to the dimensions of, for example, the housing 8, the fixing means 7, the pressure-sensing device 9, and the membrane 12) may vary depending on the symptom in question and the measurement conditions. According to an exemplary embodiment, the housing 8 may have a diameter of about 5-15 mm, and the membrane 12 may have a diameter of about 4-8 mm. However, the invention is not limited to these particular dimensions.

[0066] Furthermore, as shown in FIG. 2, the sensor device 2 includes a storage battery 16 arranged in the interior space 15, and a charging device 17 which may be configured, for example, for contactless charging of the storage battery 16 or as a device for energy harvesting.

[0067] Furthermore, the circuit board 13 is configured to divide the interior space 15 into a first subspace 15a between the circuit board 13 and the membrane 12 and a second subspace 15b between the top end portion 2b of the housing 8 of the sensor device 2 and the circuit board 13. According to one embodiment, the first subspace 15a is filled with an incompressible medium, such as air, oil, or at least one of gel / silicone.

[0068] The electronic control unit 14 is also configured to calibrate the measurements of the pressure sensing device 9 based on the existing atmospheric pressure, which contributes to accurate measurement data.

[0069] According to a further aspect, the present disclosure also relates to a method for detecting intracranial pressure by means of a sensor device 2. The method comprises a number of steps. First, an interior space 15 is provided in a housing 8 that forms part of the sensor device 2. Furthermore, the interior space 15 houses a pressure sensing device 9 and an electronic control unit 14 to which the pressure sensing device 9 is connected.

[0070] Furthermore, the method comprises the step of attaching the sensor device 2, optionally in a permanent manner, to the human skull 3 by means of fixing means 7;2b cooperating with the housing 8. Furthermore, the method also comprises the steps of: providing an opening 11 in said housing 8; covering said opening 11 with a membrane 12 made from titanium or similar thin flexible material; causing the membrane 12 to move or deflect in accordance with an existing external pressure; and The movement of the membrane is transmitted to the pressure sensing device 9 to measure the external pressure.

[0071] The invention is not limited to the above-described embodiments but can be varied within the scope of the appended claims.

Claims

1. A sensor device (2) for detecting intracranial pressure, said sensor device (2) comprising: a housing (8) defining an interior space (15a; 15b) adapted to accommodate a pressure-sensing device (9) and an electronic control unit (14) to which said pressure-sensing device (9) is connected, and - fixing means (7; 2b) cooperating with said housing (8) for mounting, optionally in a permanent manner, said sensor device (2) within the human skull (3); Including, - the housing (8) has an opening (11) covered by a membrane (12) made of titanium or a similar thin flexible material and is adapted to generate vibrations according to the external pressure present, said vibrations being transmitted to the pressure-sensing device (9); A sensor device (2) characterized in that

2. 2. The sensor device (2) of claim 1, wherein the housing (8) and the opening (11) are formed to have a substantially circular cross section, and the membrane (12) has a circular shape corresponding to the opening (11).

3. The sensor device (2) according to claim 1 or 2, wherein the membrane (12) has a thickness of less than 100 μm.

4. The sensor device (2) according to claim 3, wherein the membrane (12) has a thickness in the range of 5 to 50 μm.

5. The sensor device (2) according to any one of claims 1 to 4, wherein the sensor device (2) further comprises a storage battery (16) arranged within the interior space (15).

6. The sensor device (2) according to claim 5, wherein the sensor device (2) further comprises a charging device (17) configured for contactless charging of the accumulator (16).

7. The sensor device (2) according to any one of claims 1 to 6, wherein the sensor device (2) further comprises a charging device (17) based on a device for energy harvesting.

8. The sensor device (2) according to any one of claims 5 to 7, wherein the accumulator (16) is based on a capacitor.

9. The sensor device (2) according to any one of claims 1 to 8, wherein the housing (8) is made of titanium.

10. 10. The sensor device (2) according to any one of claims 1 to 9, wherein the pressure sensing device (9) is mounted on a circuit board (13) configured to divide the internal space (15a; 15b) into a first subspace (15a) between the circuit board (13) and the membrane (12) and a second subspace (15b) between the circuit board (13) and an end portion (2b) of the housing (8).

11. The sensor device (2) according to claim 10, wherein the first subspace (15a) is filled with an incompressible medium, a gas or a vacuum.

12. The sensor device (2) according to claim 11, wherein the incompressible medium comprises at least one of a liquid, an oil, or a gel / silicone.

13. The sensor device (2) according to any one of claims 10 to 12, wherein the pressure sensitive device (9) is mounted on the circuit board (13) on the side facing the membrane (12).

14. The sensor device (2) according to any one of the preceding claims, wherein the electronic control unit (14) is connected to a gyro (19).

15. The sensor device (2) according to any one of claims 1 to 14, wherein the electronic control unit (14) is configured to calibrate the measurements of the pressure sensing device (9) based on the existing atmospheric pressure.

16. The sensor device (2) according to any one of the preceding claims, wherein the housing (8) is formed with an area that is open to allow wireless signal transmission.

17. 17. The sensor device (2) according to claim 16, wherein the open area is covered with a sealing material such as ceramic, glass, epoxy material, silicone or the like.

18. The sensor device (2) according to any one of claims 1 to 17, wherein the pressure sensing device (9) is located entirely within an internal space (15a) formed by the housing (8), and the membrane covers the opening (11).

19. 19. The sensor device (2) according to any one of claims 1 to 18, wherein the interior space is formed by the housing (8) and the membrane (12), the membrane (12) covering the opening (11) to form a sealed housing.

20. 1. A method for detecting intracranial pressure by means of a sensor device (2), said method comprising: an internal space (15a; 15b) provided by a housing (8) forming part of said sensor device (2); The interior space (15a; 15b) accommodates a pressure sensing device (9) and an electronic control unit (14) to which the pressure sensing device (9) is connected; and Attaching said sensor device (2) to the human skull (3), optionally permanently, by means of fixing means (7; 2b) cooperating with said housing (8). and the method further comprises: providing an opening (11) in said housing (8); covering said opening (11) with a membrane (12) made of titanium or similar thin flexible material; generating movement in said membrane (12) in accordance with an existing external pressure; and transmitting said movement to said pressure sensing device (9) to measure said external pressure; A method characterized by:

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