Method and device to improve hydrocephalus shunt systems

Abstract

A method and device used to improve the operation of a hydrocephalus shunt system based on the use of alpha and beta radioactive isotopes implanted in the critical zones of the shunt in order to prevent the deposition of organic matter such as blood cells, tissue, or bacteria, thereby clogging the system and causing malfunction.

Claims

1. A method to improve the duration of good operation of hydrocephalus shunts comprising of: a. A shunt part before assembly with critical technologic surfaces accessible for ion beam; b. An implantation of an in-depth stabilization layer to prevent alpha emitter isotope diffusion in depth (for beta emitter may be applied but it is not critical); c. An implantation layer placed few microns from the surface in shunt's critical surfaces that allows alpha or beta radiation escape in nearby fluid stopping into it, and breaking the organic matter into smaller entities unable to deposit on the protected surfaces. d. An implantation of an outer layer that prevents the diffusion of the radioactive isotope to the surfaces, locking it in position, and preventing it from escaping in the fluid.

2. A method to improve the duration of good operation of hydrocephalus shunts according to claim 1 that allows control of depth and radiation type and absorbed dose.

3. A method to improve the duration of good operation of hydrocephalus shunts according to claim 1, where the radioactive implanted layer is locked in depth between two layers of materials that prevents the diffusion through of the radioactive material.

4. A method to improve the duration of good operation of hydrocephalus shunts according to claim 1 where the isotope used is customized on application type of stent and disease particularities;

10. A shunt device that improves the good operation duration and allows continuous data transfer, made of: a. An improved shunt with anti-clogging layers embedded; b. A micro-processor embedded near shunt system comprising of: i. Battery ii. Micro-processor iii. DAQ collecting information of: 1. Temperature; 2. Pressure in liquid in input, 3. Differential pressure, 4. Conductivity, 5. Other electric signals, 6. Solenoid Triggering signal and, 7. Battery voltage iv. Wi-Fi module

11. A shunt device according to claim 10 that may use Wi-Fi to connect to an external device and exchange data.

12. A shunt device according to claim 10, where the sensitive parts are made of various materials, that are suitable for being implanted with the isotope layers and be coated with materials that are rejecting the clogging.

13. A shunt device according claim 10, where the good operation is continuously reported via a wi-fi to a local data acquisition and processing unit.

14. A shunt device according to claim 10, where anticipation for maintenance program is possible to be set based on evolution of the measured parameters.

15. A shunt device according to claim 10, where the type of radioisotope and its activity is customized for the patient.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0043] FIG. 1A Hydrocephalus shunt implanted in a Human body;

[0044] FIG. 1B Shunt details;

[0045] FIG. 2 Schematic diagram of a shunt valve;

[0046] FIG. 3 Main corpuscular radiation mechanisms;

[0047] FIG. 4 Chart showing beta particles LET (Linear Energy Transfer) with distance;

[0048] FIG. 5 Details on electrons stopping in matter;

[0049] FIG. 6 Details of alpha particles kinematics in air;

[0050] FIG. 7 Alpha particles kinematics details;

[0051] FIG. 8 Valve shutter mechanism details;

[0052] FIG. 9 Radioactive layer structure;

[0053] FIG. 10 Shunt with WiFi communication;

FIGURES DETAILS

[0054] FIG. 1A Hydrocephalus stent implanted in a Human body: [0055] 100—Body; [0056] 101—Head; [0057] 102—Brain; [0058] 103—Tube inserted in hydrocephalic cavity; [0059] 104—Pressure regulator shunt; [0060] 105—plastic tube; [0061] 106—Tube discharge end in stomach.

[0062] FIG. 1B—Shunt details: [0063] 104—Pressure regulator shunt; [0064] 107—Liquid input; [0065] 108—First cavity; [0066] 109—Valve cavity; [0067] 110—Valve seat; [0068] 111—Shunt exit.

[0069] FIG. 2 Schematic diagram of a valve: [0070] 200—Valve's body; [0071] 201—Conduit opening; [0072] 202—Coil; [0073] 203—Plunger; [0074] 204—Valve stem; [0075] 205—Valve seat; [0076] 206—Plunger's spring; [0077] 207—Valve flow space; [0078] 208—Valve central lid; [0079] 209—Valve's lid rod; [0080] 210—Valve sit.

[0081] FIG. 3 Main corpuscular radiation mechanisms: [0082] 301—Alpha decay; [0083] 302—Beta decay; [0084] 303—Electron capture; [0085] 304—Ionization collision.

[0086] FIG. 4—Chart showing beta particles LET (Linear Energy Transfer) with distance: [0087] 400—Chart Linear Energy Transfer as function of Distance in lg. scale.

[0088] FIG. 5—Details on electrons stopping in matter: [0089] 500—Chart showing Range in g/cm2 versus particle energy in MeV 1 MeV=1.6 10{circumflex over ( )}−13 J;
CSDA=The continuous slowing down approximation (CSDA) range represents the path length that an electron would traverse when slowing down from its original energy E. to a stop, if its rate of energy loss along the track were equal to the mean rate of energy loss. For water density=1 g/cm3 therefore may interpret ranges in cm. [0090] 501—90Sr energy of 464 keV; [0091] 502—Range in water for this energy; [0092] 506—90 Y energy of 2.3 MeV; [0093] 507—Range for 90Y is 10 cm in water.

[0094] FIG. 6 Details of alpha particles kinematics in air: [0095] 600—Chart showing ionization density versus distance.

[0096] FIG. 7 Alpha particles kinematics details acting in Lexan, 5 micron coated by 2 micron of Au holding watery liquid: [0097] 701—Ion Ranges in the Lexan, Au, Water structure; [0098] 702—Alpha particle energy loss by ionization in the Lexan, Au, Water structure; [0099] 703—Alpha particles energy deposition into recoils in the Lexan, Au, Water structure; [0100] 704—Alpha particle energy deposition into phonons in the Lexan, Au, Water structure;

[0101] FIG. 8 Valve shutter mechanism details: [0102] 800—Valve separation structure; [0103] 801—Liquid intake cavity; [0104] 802—Liquid exhaust cavity; [0105] 803—Valve seat; [0106] 804—Liquid intake flow; [0107] 805—Liquid output flow; [0108] 806—Valve lid; [0109] 807—Valve lid's rod; [0110] 808—Protective bellow cover; [0111] 809—Radioactive surface; [0112] 810—radioactive sit surface.

[0113] FIG. 9 radioactive layer structure: [0114] 900—Material bulk; [0115] 901—Layer to stop diffusion in bulk; [0116] 902—Radioactive isotope; [0117] 903—Layer to stop diffusion outside the bulk; [0118] 904—Chemical inert layer; [0119] 905—Hydrocephalic liquid; [0120] 906—Organic molecule; [0121] 907—Radiation split molecular bound; [0122] 908—Beta Radiation passing without interaction; [0123] 909—Alpha particles; [0124] 910—Water molecule.

[0125] FIG. 10 Shunt with WiFi communication: [0126] 1000—Shunt's programing and control unit; [0127] 1001—Pressure measuring transducer; [0128] 1002—Valve position monitoring; [0129] 1003—Battery; [0130] 1004—Pressure regulator shunt; [0131] 1005—Communication and control micro-processor; [0132] 1006—RF signal; [0133] 1007—Liquid input; [0134] 1008—First cavity; [0135] 1009—Valve cavity; [0136] 1010—Valve seat; [0137] 1011—Shunt exit.

DETAILED DESCRIPTION OF THE INVENTION

[0138] The inventors consider the developments in shunt radioactive protection and Wi-fi monitoring technology may be successfully used to improve the quality and duration of operation, as well to provide a reliable and safe source of information on brain pressure in various work conditions and environments, and a tool for medical researchers and professionals involved in brain functionality, physiology and pathology.

2. Best Mode of the Invention

[0139] FIG. 10 shows the devices in the best mode contemplated by the inventors of the use of radioactive ions implantation with biometric data acquisition and processing system which solutions and developments are embedded in the present invention.

[0140] The invention corrects the following previous deficiencies of the previous devices, as follows: [0141] a)—Prevents parts of cerebrospinal fluid (CSF) to clog sensitive parts of the shunt, triggering its mal-operation as shunt failure or infection; [0142] b)—Makes a system that gives a quasi-real time data on intracranial pressure (ICP) that may be correlated with other internal and external parameters to better understand the mechanisms that are involved; [0143] c)—Is easy, adaptable to new types of shunts, and appears for shunt manufacturers as another stage in shunt production; [0144] d)—It is versatile, allowing various types of radioisotopes to be used, inside the limits of safety for the patient and physicians; [0145] e) Improves the warning and alert to the health provider, by detecting any anomalous evolution of the patient, based on customized data sets.

[0146] The best application of the invention is explained in FIGS. 8-10 and done by the system presented in FIG. 10. The system allows multiple active modes, with various technical combinations of ICP, as function of customized patient conditions and presentation of the integrated data, in such manner that each participant evolution to be possible to be analyzed in the smallest detail.

3. How to Make the Invention

[0147] As can be amply seen from the drawings the procedure includes a device that is made of a micro-processor board for data acquisition, mainly absolute pressure, and differential pressure on the shunt valve, temperature, liquid's electric conductivity, and shunt valve control signal and position, and possible other electric or magnetic signal additionally acquired from the brain, from which based on calibration the liquid flow and brain activity may be calculated. The wi-fi communication system assures data monitoring and in some cases shunt operation reprograming and optimization.

[0148] The method to produce a more robust shunt using radioactive isotopes relies on the fact that at interaction between radiation and matter radiolysis process occurs that breaks molecular bonds producing free radicals, that further may recombine producing shorter molecules and recombine, fulfilling open bounds/valences modifying the surface tension and adhesion forces and making cerebrospinal fluid (CSF) more fluid and less likely to deposit and clog the shunt's technological surfaces.

[0149] The method has the following steps: [0150] a)—Determine in cooperation with shunt manufacturer the surfaces of interest to be implanted; [0151] b)—The manufacturer delivers the parts of interest specifying the materials used; [0152] c)—The isotope of interest and type of charged particle is established; [0153] d)—Radiation transport code is applied to calculate radiation dose distribution inside the volume and outside the stent in the head area and around, confirming that all safety measures have been considered and applied; [0154] e) If the selected charged particle is: [0155] a. An alpha particle the procedure of implantation has the following steps: [0156] i. Implant first a diffusion stopper material at a depth of several microns (that can be Au, Ag, W, etc.); [0157] ii. Implant the radioactive isotope with a range with 1-2 microns smaller than the previous implantation; [0158] iii. Implant another diffusion stopper layer at a range from surface down to the upper edge of the radioactive isotope layer; [0159] iv. Make a coating of few microns of a material chemically inert and with good properties for wear, corrosion, abrasion and affinity inside cerebrospinal fluid (CSF); [0160] b. A beta (electron) particle: [0161] i. Due to larger range of electrons the inside diffusion blocker layer is not needed except special circumstances when other considerations recommends it; [0162] ii. All the rest of steps remain the same; [0163] f) Quality assurance (QA) methods are applied to certify the conformity of the work with the previous planning and computer simulations that may use, but not limited to the following techniques: [0164] a. Charged particle and associated X, gamma spectrometry; [0165] b. Rutherford Back-Scattering (RBS); [0166] c. Micro-profile measurements; [0167] d. Autoradiography, where is possible; [0168] g) With the QA certificate the parts are delivered to manufacturer to assembly them and perform the final QA measurements and calibration of the whole system before being implanted inside patient's skull; [0169] h) Before ending the surgery the final tests of the system are made, certifying that the entire parameter set is according with the plan and overall system QA certificate may be released; [0170] i) Based on calibrations made by manufacturer the operation data acquisition and processing starts and the normal usage starts.

[0171] Together the method and device is aimed to assure a long period of good operation of the stent, while each patient monitoring will add to database helping the R&D effort in the brain and neuro-science, s identifying best operation pressures for various brain regimes.

DETAILED DESCRIPTION OF THE FIGURES

[0172] FIG. 1A—Shows a hydrocephalus shunt implanted in a Human body, 100, where the main part is implanted inside Head, 101, near the Brain, 102, having a tube, 103, inserted in hydrocephalic cavity. The pressure regulator shunt, 104, discharges the excess fluid using a bio-compatible plastic tube, 105, with the tube discharge end, 106, in stomach from where the liquid is further eliminated.

[0173] FIG. 1B shows a detail on shunt, 104, that acts as a intracranial pressure (ICP) regulator by taking in its liquid input, 107, cerebrospinal fluid (CSF) in its first cavity, 108, measuring its pressure and passing it in valve cavity, 109, placed on a valve seat, 110, that when ICP is higher than normal valve opens, releasing ICF into shunt exit, 111, tube and from there in the stomach.

[0174] FIG. 2 shows a Schematic diagram of a valve where valve's body, 200, is made of bio-compatible plastics, with null-buoyancy inside the head, being actuated by an electromagnetic coil, 202, powered by electric cables via a conduit opening, 201, bringing power from a battery and control device. The coil actuates a plunger, 203, that pushes valve's stem, 204, moving the valve's central lid, 208, up and down from the valve's seat, 205, opening and closing valve flow space, 210. The plunger, 203, is connected via an extension rod, 207, and a smaller in diameter valve's lid rod, 209, to the valve lid, 208, compressing between a plunger's spring, 206.

[0175] FIG. 3 shows briefly main corpuscular radiation mechanisms, where alpha particles which are He nuclei are the result of Alpha decay, 301, the electrons result from beta decay, 302, or from electron capture, 303, or ionization collision, 304, and any of these reactions are used in our application.

[0176] FIG. 4 presents a chart showing beta particles LET (Linear Energy Transfer) with distance where in chart, 400, LET is given as function of distance in lg. scale for the radiation energy specific to various isotopes.

[0177] FIG. 5 gives more details on electrons stopping in matter, with respect to CSDA (The continuous slowing down approximation (CSDA)) range represents the path length that an electron would traverse when slowing down from its original energy E to a stop, if its rate of energy loss along the track were equal to the mean rate of energy loss. For water density=1 g/cm.sup.3 therefore may interpret ranges in cm, in chart, 500, showing Range in g/cm.sup.2 versus particle energy in MeV (1 MeV=1.6 10.sup.−13 J). The stopping range for .sup.90Sr, 501, which has a maximum energy of 464 keV, showing range in water, 502, for this energy, and for .sup.90Y, 506, with maximum energy of 2.3 MeV, showing range in water, 507, for .sup.90Y.

[0178] FIG. 6 shows some details of alpha particles kinematics in air, where is given a chart showing ionization density versus distance, 600.

[0179] FIG. 7 presents more alpha particles kinematics details as it seems that these particles having a shorter range in water may be more effective for our purpose. In the lower left side is given Ion Ranges of 5 MeV alpha particles in watery liquid, 701. Alpha particle energy loss by ionization, 702, is plotted in upper left side showing its path through 5 microns of Lexan, 2 microns of gold and the rest is deposited in water. Considering that every 100 eV of deposited energy breaks about 5-6 water molecules we see that every angstrom in water harvest enough energy for 1 radiolysis, while a water molecule has about 3 angstroms. That allows us to calculate the radiolysis rate, and radiation absorbed dose. Alpha particles energy deposition into recoils, 703, is shown in upper right plot that shows that each ion basically recoils and dissociates a water molecule at the end of range that adds to the radiolysis due to ionization. Alpha particle energy deposition into phonons, 704, plotted in the lower right side shows that at the end of alpha particle range temperature per water molecule may be as high as 12 eV, that correspond to about 140,000 K degrees, that corresponds to a plasma state, for a volume of about 2 microns. This is so called Bragg peak, which in water behaves as a micro-cavitation. Here we estimate that about 1 million of molecular bounds are broken per each particle, and because ICF has only few percent of organic matter probability those organic matter radicals to be terminated short with water free radicals is high, driving to decrease in viscosity and probability of clogging on plastic internal surfaces of the shunt.

[0180] FIG. 8 shows some valve shutter mechanism details, where the valve wall is presented as valve's separation structure, 800, having a liquid intake cavity, 801, and a liquid exhaust cavity, 802, separated by valve's seat, 803, and valve's lid, 806, actuated by valve lid's rod, 807, that has a protective bellow cover, 808, that may be immune to cerebrospinal fluid (CSF) deposition. When the intracranial pressure (ICP) grows over acceptable limit, valve opens making liquid intake flow, 804, pass through the space between valve's lid, 806 and valve's sit, 803, and forms the liquid output flow, 805, towards the stomach, making intracranial pressure (ICP) decrease. The most sensitive parts to clogging are the valve's lid surface that is treated and turns into a radioactive surface, 809, and sit's shutting surface that becomes radioactive sit surface, 810, preventing both clogging and infections in the area, because radiation also damages bacteria and virioli, and not only organic residues in the cerebrospinal fluid (CSF).

[0181] FIG. 9 shows the radioactive layer structure for alpha emitter implantation, where material bulk, 900, is first implanted with a layer to stop diffusion in bulk, 901, than radioactive isotope, 902, is added at a lower depth, and over it towards the surface a layer to stop diffusion outside the bulk, 903, is implanted, such as to lock in place the radioactive emitter material. A chemical inert layer, 904, is deposited to further improve functionality and interaction with hydrocephalic liquid, 905, and minimize wear, corrosion or chemical interaction and organic matter deposition.

[0182] Figure also shows how radiation split molecular bound, 907, of any organic molecule, 906, where beta radiation may be passing without interaction, 908, having a large path than alpha particles, 909, in an organic matter dominated by water molecules, 910, splitting them in shorter radicals.

[0183] FIG. 10 shows a shunt with Wi-Fi communication, made of an actual shunt, to which a shunt's programing and control unit, 1000, have been added, containing a pressure measuring transducer, 1001, valve position monitoring, 1002, battery, 1003, pressure regulator shunt, 1004, communication and control micro-processor, 1005, that uses an RF signal, 1006, to with outside body equipment, that may be a dedicated device, cell-phone or computer. The shunt has its usual liquid input, 1007, in the first cavity, 1008, and from there in the valve cavity, 1009, then passing through valve seat, 1010, when valve is open through shunt's exit tube, 1011, towards stomach.

[0184] Private industry would be employed to build the many units required as accessories to form a new product addressing these most critical situations. It was conceived to keep the cost as low as possible, to be largely accessible, and make a drastic improvement in the way the most important part of the sickness cycle is treated. Being equipped with an expert program, it will make a difference, in sickness assistance, predicting the need for emergency care, in the situations when medication and reprograming is inefficient, being possible to connect in real-time with physician, and seek emergency response, or treating a disease in ambulatory conditions.

EXAMPLES OF THE INVENTION

[0185] Thus it will be appreciated by those skilled in the art that the present invention is not restricted to the particular preferred embodiments described with reference to the drawings, and that variations may be made therein without departing from the scope of the present invention as defined in the appended claims and equivalents thereof. The present invention consists in development of a method to implant radioactive isotopes in the critical technologic surfaces of the shunt, to improve its good operation duration, and using Wi-Fi connected local embedded data acquisition (daq) system to have compressive bio-metric and medical evaluation and improve the research data base with new reliable information.

[0186] The invention may be also applied in very complex situations, allowing the users to get complex data, as for scientific purposes or to test new prototypes.

[0187] The present invention relies on the customization of the data acquisition equipment to serve the most urgent needs, fulfilling the gap between computer simulators and real life, where patient's biometric evaluation in possible simultaneously with the normal operation.