Cerebrospinal-fluid-pressure-measuring device

Patent metadata

Field	Value
Publication number	US-11957442-B2
Application number	US-201916591912-A
Country	US
Kind code	B2
Filing date	Oct 3, 2019
Priority date	Oct 3, 2019
Publication date	Apr 16, 2024
Grant date	Apr 16, 2024

Abstract

A cerebrospinal-fluid-pressure-measuring device including a pressure gauge including a hollow cylindrical body for inserting through a skull and having a lower and upper end, and an inner surface, a membrane attached to the lower end and to move under a pressure of cerebrospinal fluid within the skull, and coils including a stationary coil disposed in the cylindrical body and connected to the inner surface so as to remain stationary, and a moving coil disposed in the cylindrical body and connected to the membrane so that the moving coil moves when the membrane moves under the pressure, one of the coils being configured as a transmitting coil and another of the coils being configured as a receiving coil, and a control unit to apply an input signal to the transmitting coil and receive an output signal from the receiving coil, and to generate an indication of the pressure.

First claim

What is claimed is:

1. A cerebrospinal-fluid-pressure-measuring device, comprising:
a pressure gauge including:
a hollow cylindrical body configured for inserting through a skull and having a lower end, an upper end, a length measure from the lower end to the upper end extending in a length direction, an inner surface extending along the length direction of the hollow cylindrical body, an outer surface, and a cavity defined by the inner surface from the lower end towards the upper end, wherein the upper end of the hollow cylindrical body includes a drive or bolt head to aid in screwing the pressure gauge into the skull for fastening therein;
a membrane attached to the lower end so as to at least partially seal the cavity, the membrane being configured to move under a pressure of cerebrospinal fluid within the skull; and
a plurality of coils including a stationary coil and a moving coil, the stationary coil being (i) disposed in the cavity of the hollow cylindrical body, (ii) connected to the inner surface of the hollow cylindrical body so as to remain stationary with respect to the hollow cylindrical body, and (iii) extending along the length direction along the inner surface, the moving coil being disposed in the cavity of the hollow cylindrical body, extending along the inner surface, and directly connected to the membrane so that the moving coil moves with respect to the stationary coil when the membrane moves under the pressure from the cerebrospinal fluid, one of the stationary coil or the moving coil being configured as a transmitting coil and another of the stationary coil or the moving coil being configured as a receiving coil; and
a control unit comprising a memory and a processor configured to contact the upper end of the hollow cylindrical body so as to apply an input signal to the transmitting coil and receive an output signal from the receiving coil in response to the input signal, and to generate an indication of the pressure of the cerebrospinal fluid responsively to the output signal.

2. The device according to claim 1 , wherein the outer surface of the hollow cylindrical body is threaded so as to enable screwing the pressure gauge into the skull for fastening therein.

3. The device according to claim 1 , wherein the moving coil has a first axis and the stationary coil has a second axis, the first axis being substantially parallel to the second axis.

4. The device according to claim 3 , wherein the first axis is substantially collinear with the second axis.

5. The device according to claim 4 , wherein a separation of the moving coil and the stationary coil in the direction of the first axis and the second axis is in the range of 0.05 mm to 0.7 mm.

6. The device according to claim 1 , wherein the hollow cylindrical body had an outer diameter in the range of 0.5 mm to 3.5 mm.

7. The device according to claim 1 , wherein the hollow cylindrical body includes a tapered cylinder.

8. The device according to claim 7 , wherein: the lower end of the hollow cylindrical body has an outer diameter in the range of 0.5 mm to 3.2 mm; the upper end of the hollow cylindrical body has an outer diameter in the range of 0.7 mm to 3.5 mm; and the hollow cylindrical body has a length measure from the lower end to the upper end in the range of 3-8 mm long.

9. The device according to claim 7 , wherein the outer surface of the hollow cylindrical body is threaded so as to enable screwing the pressure gauge into the skull for fastening therein.

10. The device according to claim 1 , wherein the cavity is hermetically sealed.

11. The device according to claim 1 , wherein the membrane includes a silicone.

12. The device according to claim 11 , wherein the silicone includes polydimethylsiloxane (PDMS) having a chemical formula of CH 3 [Si(CH 3 ) 2 O] n Si(CH 3 ) 3 .

13. The device according to claim 1 , wherein the control unit is reversibly attachable to the upper end of the hollow cylindrical body.

14. The device according to claim 13 , wherein the control unit and the upper end include complementary interconnecting features to secure the control unit to the hollow cylindrical body.

15. The device according to claim 14 , wherein the complementary interconnecting features includes a plurality of electrical connections configured to electrically connect the control unit with the plurality of coils.

16. The device according to claim 15 , wherein the control unit is configured to generate the indication of the pressure of the cerebrospinal fluid and store the indication in the memory.

17. The device according to claim 16 , wherein the control unit includes a power supply, and a data interface, which is configured to provide the indication of the pressure stored in the memory to a remote processing device.

18. The device according to claim 1 , wherein the transmitting coil and the receiving coil each have between 10 and 30 winds per coil.

19. The device according to claim 1 , wherein the transmitting coil and the receiving coil each are made from wire with a thickness in the range of 0.01 mm to 0.05 mm.

20. A pressure gauge device, comprising:
a hollow cylindrical body for inserting through a skull and having a lower end, a length measure from the lower end to the upper end extending in a length direction, an upper end, an inner surface extending along the length direction of the hollow cylindrical body, an outer surface, and a cavity defined by the inner surface from the lower end towards the upper end, the hollow cylindrical body including a tapered cylinder, wherein the upper end of the hollow cylindrical body includes a drive or bolt head to aid in screwing the pressure gauge device into the skull for fastening therein;
a membrane attached to the lower end so as to at least partially seal the cavity, the membrane being configured to move under a pressure of cerebrospinal fluid within the skull, the outer surface of the hollow cylindrical body being threaded so as to enable screwing the pressure gauge into the skull for fastening therein; and
a plurality of coils including a stationary coil and a moving coil, the stationary coil being (i) disposed in the cavity of the hollow cylindrical body, (ii) connected to the inner surface of the hollow cylindrical body so as to remain stationary with respect to the hollow cylindrical body, and (iii) extending along the length direction along the inner surface, the moving coil being disposed in the cavity of the hollow cylindrical body and directly connected to the membrane so that the moving coil moves with respect to the stationary coil when the membrane moves under the pressure from the cerebrospinal fluid, one of the stationary coil or the moving coil being configured as a transmitting coil and another of the stationary coil or the moving coil being configured as a receiving coil, wherein:
the upper end is configured for interconnecting with a complementary feature of a control unit comprising a memory and a processor, which is reversibly attachable to the upper end of the hollow cylindrical body;
the upper end includes a plurality of electrical connections configured to electrically connect the control unit with the plurality of coils;
the control unit is configured to contact the upper end of the hollow cylindrical body so as to apply an input signal to the transmitting coil and receive an output signal from the receiving coil in response to the input signal, and to generate an indication of the pressure of the cerebrospinal fluid responsively to the output signal.

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Assignees

• Biosense Webster Israel Ltd

Inventors

• Govari Assaf
• Sitnitsky Ilya
• Algawi Yehuda

Classifications

• A61B5/032 Primary

  Spinal fluid pressure · CPC title

• A61B5/6864

  Burr holes · CPC title

• A61B2562/0247

  Pressure sensors · CPC title

• G01L9/007 Primary

  using variations in inductance · CPC title

• A61B5/6868

  Brain · CPC title