Measuring device and corresponding method for non-invasive detection of intracranial pressure in a patient

Abstract

The application discloses a measuring device for noninvasive detection of intracranial pressure pulsation of a patient, comprising: a holder which is detachably attached to the outside of the skull of the patient in a force-fitting and / or form-fitting manner; at least one double-gusset bending sensor which is arranged in or on the holder; an analog signal amplifier for amplifying the measurement data provided by the double-gusset bending sensor; an A / D converter for converting the analog measurement data into digital data; and a computing unit for preprocessing the data and calculating life parameters such as intracranial pressure based on the digital data. The application also discloses a related method for noninvasive detection of intracranial pressure pulsation.

Description

Technical Field

[0001] This invention relates to a measuring device for non-invasive detection of intracranial pressure in patients. Background Technology

[0002] Many critical neurological conditions can involve life-threatening increases in intracranial pressure (ICP). The internal volume of the skull remains constant, so an increase in the volume of one or more compartments can lead to elevated ICP. These compartments include brain tissue (e.g., due to hemorrhage, swelling, and inflammation), CSF space (e.g., due to hydrocephalus and hemorrhage), and vascular spaces (e.g., due to changes in hyperventilation or hypoventilation). The relationship between intracranial volume and intracranial pressure is called intracranial compliance. Initially, an increase in ICP may be compensated for by so-called reserved space (CSF space, vascular spaces) (Monro-Kellie hypothesis), but as the volume increases, ICP also increases exponentially. Conditions that can lead to increased pressure include traumatic brain injury, epidural / subdural hematoma, space-occupying ischemic stroke, intracerebral hemorrhage, subarachnoid hemorrhage, venous sinus / cerebral vein thrombosis, meningitis, encephalitis, global cerebral hypoxia, and other conditions such as brain tumors, poisoning, and metabolic disorders.

[0003] To enable uninterrupted monitoring of intracranial pressure (ICP) in critical situations such as severe traumatic brain injury, a measuring catheter can be invasively inserted through the top of the skull. However, the invasive measurement process can be burdensome for many patients, often leading them to abandon monitoring altogether.

[0004] Non-invasive measurement methods based on measuring skull extension have been proposed. Blood volume fluctuations caused by heartbeats lead to skull extension, especially across the cranial sutures where connective tissue closes. The resulting intracranial pressure pulsations are approximately 3-4 mmHg, which in turn cause, at a minimum, synchronous expansion of intracranial pulsations.

[0005] Patent document WO2013 / 041973A2 discloses a measuring device for non-invasive measurement of intracranial pressure, including a sensor configured to detect skull deformation. The sensor is connected to an amplifier, an A / D converter, a processor, a display, and a memory. The measuring device can determine intracranial pressure by evaluating the sensor signal and determine skull deformation based on the sensor signal.

[0006] Patent document WO2019 / 087148A1 discloses a similar measuring device in which data collected by a sensor is processed and wirelessly transmitted to a receiver.

[0007] However, a drawback of such measuring devices is that the significant influence of external carotid artery pulsation cannot be eliminated due to the lack of decoupling. Skull pulsation caused by pulsating intracranial pressure is significantly smaller than arterial pulsation; without distinguishing between arterial and intracranial pulsation, skull pulsation becomes largely meaningless. The strain gauge arrangement proposed in the aforementioned literature operates within its measurement limits. This also means that it is impossible to have padding on the measuring device on the skull; therefore, prolonged use will cause significant discomfort to the patient over time. Summary of the Invention

[0008] The purpose of this invention is to provide a measuring device for non-invasive detection of intracranial pressure pulsation, which overcomes the above-mentioned shortcomings and can simply and reliably measure vital data such as static intracranial pressure.

[0009] To achieve the above objectives, the present invention proposes a measuring device having the features described in claim 1.

[0010] The measuring device of the present invention includes: a retainer that can be detachably attached to the outer side of a patient's skull in a force-fit and / or shape-fit manner; at least one double-layer bending sensor disposed within or on the retainer; an analog signal amplifier and / or an analog signal filter for amplifying and / or filtering the measurement data provided by the double-layer bending sensor; an A / D converter for converting the analog measurement data into digital data; and a computing unit for preprocessing the digital data and calculating and / or deriving vital parameters such as intracranial pressure based on the digital data.

[0011] The measuring device of this invention is characterized by largely eliminating the influence of arterial pulsation, meaning that what is actually measured is intracranial pressure pulsation. In addition to adjusting the digital data, the calculation unit is also used for calibration and to calculate characteristic curve parameters and values ​​that can be derived from them, such as intracranial pressure (ICP). Furthermore, systolic or diastolic characteristic values ​​or vital parameters can be derived from the digital data. Optionally, the measuring device of this invention includes a display so that it can output amplitude curves, measurement curves, determined parameters, derived values, or warnings.

[0012] The present invention is based on the recognition that a double-layered bending sensor can be used to provide a particularly simple yet reliable and accurate measurement of intracranial pressure pulsations. The principle of the invention is based on the fact that a double-layered bending sensor attached to a headband or head contact surface is deflected by the pulsating intracranial volume expansion caused by the pulsating intracranial pressure (ICP).

[0013] Piezoelectric bending sensors can measure even the smallest skull deformations or vibrations caused by a heartbeat. Because the transmission pathway passes through brain tissue, the blood pressure pumped from the heart into the brain gradually decreases during a heartbeat. Transmission function sometimes depends on intracranial pressure and related autoregulatory mechanisms; therefore, the dynamic pressure drop process can be particularly used to infer intracranial pressure and autoregulatory status.

[0014] Preferably, the retainer is configured as a headband or headband. However, the retainer can also be attached alternatively by laying, bonding, or clamping the bending sensor with a reed cap or bandage. It is also conceivable to use a suitable elastic coupling medium, such as a skin-friendly double-sided adhesive film, specifically or additionally.

[0015] The measuring device includes a headband or headband that is at least partially flexible and resistant to bending, and at least partially elastically stretchable. The tension of the headband or headband is adjustable. At least one bending sensor is part of the flexible bending segment of the headband or headband, which may be statically or dynamically bent directly by static or dynamic volume expansion of the skull or by changes in the tension stress of its attached support (particularly the headband). The headband can be applied to the patient's head and secured with a constant tension by a tensioning device.

[0016] Preferably, the bending sensor is a double-layer piezoelectric bending sensor. The bending sensor can be a double-layer bending sensor with antiparallel polarities. In this case, the following effect is utilized: the pressure pulsation of the skull, where the measuring device of the present invention is installed, causes dynamic volume deviation, resulting in dynamic tension stress on the measuring device (configured as a headband) and dynamic bending at the location of the bending sensor. Therefore, even extremely slight pressure-induced volume changes in the skull can be detected.

[0017] The dual-layer bending sensor consists of two sensor layers symmetrically arranged around a neutral fiber. When this arrangement bends in one direction, one sensor-activated bending sensor layer extends while the other sensor-activated bending sensor layer compresses equally. When this arrangement bends in the other direction, the behavior is exactly the opposite. Due to the antiparallel polarity of the two sensor layers, the signals from these opposite loads have the same sign, and when added together, the overall signal is enhanced. On the other hand, synchronization effects such as interference temperature effects or thermoelectric effects are largely canceled out and thus compensated.

[0018] In addition to double-layer piezoelectric bending sensors, multi-layer bending sensors consisting of several pairs of sensors with alternating antiparallel polarities can also be used.

[0019] It can be proposed that the bending sensor be arranged in a rocker-like manner on a support that can be attached to the outside of the patient's skull. In this embodiment, the bending sensor is arranged on the support, which is positioned in the patient's cranial suture region. The double-layered piezoelectric bending sensor can move about a pivot point in a rocker-like manner under the influence of skull volume deviation. When the retainer is configured as a headband, a predetermined preload is applied to the bending sensor to generate the reaction force (support force) necessary for bending.

[0020] In an alternative embodiment, the bending sensor is positioned in the middle section between the two distal segments of a C-shaped support. The C-shaped support is placed on the patient's skull such that the two distal segments are positioned on either side of the cranial suture. Pulsation of the skull causes volumetric deviation, resulting in the two distal segments (legs) of the C-shaped support moving in opposite directions, causing the middle section of the bending sensor to bend. The attachment of the bending sensor ensures that no or negligible pulsation is transmitted to the bending sensor via an external artery or vein. This can be achieved by ensuring that the pulsating artery or vein has no contact or only strong damping mechanical contact with the bending sensor or its attachment (i.e., the headband). For this purpose, the C-shaped support of the measuring device of the present invention allows for easy and effective bridging of strongly pulsating external vessels such as aortas. Furthermore, this can be achieved in other locations using recesses on the support. With the use of sponge padding, the influence of smaller and therefore weaker pulsating external vessels can also be effectively reduced to below the influence limit. Direct or insufficiently damped contact with pulsating arteries can be immediately detected in the time signal through the typical "arterial curve shape" and significantly higher amplitude.

[0021] Another alternative embodiment proposes securing the C-shaped support around the head like a headband using a headband or strap. This allows pulsating volumetric deviations to be transmitted as tension stress in the headband or strap, which in turn causes the legs of the C-shaped support to bend accordingly, detected by a bending sensor. This headband allows the minimum volumetric deviation of the skull to be transmitted as tension stress to the C-shaped legs of the sensor support. This also causes the C-arms to bend, detected by a bending sensor.

[0022] This headband generates a defined preload. Changes in the intracranial volume due to intracranial pressure pulsations cause the piezoelectric bending sensor to bend, which can be detected by the measuring device of this invention. Using the measurements obtained in this way, intracranial pressure pulsations and their waveforms can be monitored, and vital state variables such as intracranial pressure can be calculated from the characteristics and characteristic values ​​of the pressure pulse waveforms. The C-shaped support can also be inverted on the patient's skull, i.e., with both distal segments extending away from the skull. In this case, the headband also generates a preload. The double-layered bending sensor can be placed on either side of the midsection or symmetrically on both sides of the midsection. Alternatively, in this example, as in all other examples, the double-layered bending sensor can be placed in the neutral fibers of the midsection. It is also possible that multiple piezoelectric bending sensors are symmetrically arranged about the neutral fibers inside the midsection. A soft, elastic support pad can also be placed on the outer side of the skull to which the C-shaped support is attached. Alternatively, the pad can be attached to the headband in a quick-replaceable manner.

[0023] Preferably, when the retainer is configured as a headband, it may have a preload generator for generating and adjusting the preload force acting on the patient's skull. Preferably, the preload generator may include a force sensor or strain sensor. The user can adjust the preload force via a handwheel or alternatively via a motor. For this purpose, the preload generator may include a linear elastic tension member, such as a tension spring. In another embodiment, after a constant tension stress is established, the linear elastic tension member can be fixed, i.e., locked, relative to a further offset.

[0024] In this context, preferably, the preload generator has an indicator for indicating the preload or the associated tension. This allows the user to set and control a specific preload transmitted through the headband to the piezoelectric bending sensor.

[0025] To further simplify the use of the measuring device of the present invention, the preload generator can be configured to automatically set a predetermined preload. For this purpose, an electromechanical or pneumatic mechanism can be provided. Manual or automatic control of the preload can be achieved by adjusting the pneumatic tension using an integrated air cushion combined with a pressure sensor.

[0026] Optionally, the headband may have padding along at least a portion of its length. The padding may also consist of several separate padded support points. The padding is located inside a retainer configured as a headband. The padding may include elastic foam or viscoelastic memory foam. The headband or headband may make full contact or only contact at defined contact areas or points to minimize interference from pulsating soft tissues such as peripheral blood vessels and muscle activity, or to avoid contact with wounds.

[0027] It can also be proposed that the measuring device of the present invention has one or more structured acoustic sensors and / or one or more acceleration sensors, one or more position sensors and / or one or more pulsation sensors and / or one or more blood pressure sensors and / or temperature sensors, and the computing unit is configured to detect external interference effects through at least one of the aforementioned sensors. Once such external interference effects are detected, they can be eliminated through calculation, thereby not negatively affecting the measurement of intracranial pressure.

[0028] Preferably, the bending sensor can be removed and replaced from the support configured as a headband. The preferred sensor location on the headband or headband is provided with a recess and / or a retainer such as a clamp to secure the sensor, thereby establishing a form fit and / or force fit. However, the bending sensor can also be adhesively attached and / or screwed to the headband or headband. The headband can be reused for other patients after sterilization. The headband may also have different bending sensor attachment locations. It is also possible that several bending sensors are attached to the headband.

[0029] One embodiment of the measuring device of the present invention proposes that the dual-layer bending sensor and the analog signal amplifier are integrated into a single component. Alternatively, the following components may also be integrated into a single component: an A / D converter, a transmitter, a wireless data transmission transceiver, a battery, and a rechargeable battery. This reduces the number of components, and the measuring device requires only a small installation space.

[0030] It can also be proposed that the measuring device includes a data logger connected to an A / D converter or computing unit. The data logger stores the measurements from the bending sensor and / or data derived therefrom, such as intracranial pressure. Therefore, the data stored in the data logger can also be evaluated later. Thus, the measuring device of the present invention can also be designed as a mobile device.

[0031] When the retainer is configured as a headband, it may include an energy storage device, preferably a battery or rechargeable battery, thereby enabling its use as a mobile device.

[0032] Further applications are possible when a piezoelectric bending sensor and / or analog signal amplifier and / or A / D converter are connected to a transmitter or wireless data transmission transceiver. In this case, the data collected by the sensor can be transmitted to the receiver, preferably after amplification or conversion to digital data. With wireless data transmission, the retainer, when configured as a headband, eliminates the need for any wired connections, simplifying and facilitating operation.

[0033] A variation of the measuring device of this invention proposes that several piezoelectric bending sensors be arranged on the headband. This allows for the measurement of intracranial pressure pulsations and intracranial pressure at several points.

[0034] Furthermore, the present invention relates to a method for noninvasively detecting intracranial pressure pulsations in a patient using a measuring device having the type described in claim 17. The method comprises the following steps: attaching a retainer in the form of a headband having at least one double-layered bending sensor to the lateral side of the patient's skull in a force-fit and / or shape-fit manner; dynamically recording skull deformation and / or vibration caused by the patient's heartbeat using at least one bending sensor; calculating characteristic curve parameters based on the skull deformation and / or vibration detected by the bending sensor and based on the measured pulsation curve; and deriving vital state variables, such as intracranial pressure (ICP).

[0035] The above method may also include the following steps: digitizing the feature parameters, preprocessing the signal, and determining them.

[0036] In the method of this invention, preferably, dynamic recording of skull deformation and / or vibration is used to measure the "pressure response function" resulting from cardiac pulsation, from which intracranial pressure and other parameters related to various vital state variables are calculated. For example, this process can be used for the following diseases or conditions: head trauma, vasospasm, infarction, embolism, reperfusion, revascularization, tension headache, migraine, carotid artery stenosis embolism detection, dementia, hydrocephalus, brain tumor, sickle cell anemia, vascular malformation, meningitis, encephalitis, coma, heart failure, aortic stenosis, aortic regurgitation, aortic valve repair, carotid revascularization, aortic dissection, cardiopulmonary shunt, anesthesia, hyperventilation, catecholamines, volume management, hemofiltration, hemodialysis, pulmonary hypertension, renal insufficiency, hemodialysis, and peritoneal dialysis.

[0037] A variation of the method of the present invention proposes to use two or more bending sensors arranged in front of the skull base to detect cranial deviation pulsation caused by intracranial pressure pulsation and / or its effect.

[0038] Alternatively or additionally, two or more bending sensors located on the occipital bone at the base of the skull can be used to detect intracranial pressure.

[0039] Preferably, the method of the present invention is performed continuously, while vital parameters and intracranial pressure are recorded or derived at fixed intervals. This also allows for long-term monitoring of the patient.

[0040] In the method of the present invention, at least one bending sensor can be attached to the skull by laying, bonding, or clamping. Preferably, a retainer configured as a headband is used for this purpose.

[0041] Alternatively, at least one bending sensor may be attached to the skull as an insert of the exoskeleton or helmet. This ensures uniform contact pressure from one or more sensors.

[0042] The present invention also includes computer programs suitable for the following functions:

[0043] - Detect the initiation (start and end) of each pulsation process (pulsation curve);

[0044] - Detect interference signals (from coughing, talking, moving, etc.);

[0045] - Identify unassessable trajectories (e.g., due to interference);

[0046] - Utilize supervised (e.g., training neural networks) and / or unsupervised (e.g., cluster analysis) machine learning procedures (artificial intelligence) to evaluate the curve trajectory;

[0047] - Monitor other vital signs (breathing, blood pressure, mood, etc.);

[0048] - Correct or filter signal drift superposition (e.g., caused by breathing);

[0049] - Determine the number, location, and amplitude of curve features such as peaks, troughs, and inflection points from each pulsation curve;

[0050] - Determine the characteristic parameters that describe the direction of the curve;

[0051] - Statistical data (mean, distribution, dispersion, and trend) that determine the characteristics of the curve;

[0052] - Determine the area under the drift-corrected pulsation curve or its designated segments (especially the systolic and diastolic intervals);

[0053] - When determining parameters, distinguish between the systolic curve segment and the diastolic curve segment;

[0054] - To form any relationship between two or more parameters determined from a curve or individual curve segments.

[0055] For example: P2 / P1, P2 / P1 / A total , |P12-P32| / P1 / P3, |P12-P32| / A total A sys / A dia ;

[0056] - Establish various relationships between at least one parameter and / or the relationships between these parameters and other medical indicators (blood pressure, pulse, blood values, body temperature, etc.) and patient parameters (age, gender, weight, height, place of origin, skull geometry, motor ability, etc.);

[0057] - These values ​​are evaluated by mean and statistical assessment (distribution function parameters) based on the assessment of several pulsation curves;

[0058] - Trend curves of each parameter and their interrelationships;

[0059] - Derive diagnostic variables such as intracranial pressure (ICP), cerebral blood flow (CBF), cerebral perfusion pressure (CPP), cerebrovascular resistance (CVR), arterial pressure / mean arterial pressure (AP / MAP), pulsatility index (PI), resistance index (RI), systolic blood pressure / diastolic blood pressure (S / DP), and systolic blood pressure / diastolic blood pressure time index (SPTI / DPTI).

[0060] - Deducing self-regulation disorders or abnormalities;

[0061] - Derive typical disease characteristics from the above parameters and relationships;

[0062] - Deriving infectious diseases;

[0063] - Derive the correspondences between other vital parameters, athletic performance, medication intake, work stress, and mental illness and various health conditions or diseases, physical and mental stress states, relaxation states, and external influences.

[0064] Because of its extremely high signal quality, it can, in particular, independently assess the diastolic blood pressure curve range and derive data for the entire application domain.

[0065] Using the measuring device of this invention, clear curve characteristics can be obtained from the diastolic pressure curve range, unlike other methods such as transcranial Doppler, which obtains, for example, diastolic flow velocity curves. These curve characteristics contain important information about the effects of lesions and diseases, which may be attributed to microcirculatory disturbances, increased tissue resistance, elevated intracranial pressure, chronic inflammation, arteriosclerosis, diabetes, insufficient O2 or CO2 exchange, hypotension, or hypovolemia. Therefore, pathological lesions in these areas can be detected early without invasive procedures, and progressive lesions can be easily monitored. Furthermore, the treatment effects in these areas can be more easily evaluated, thereby providing more targeted guidance for therapy. Attached Figure Description

[0066] The present invention will now be described with reference to the accompanying drawings and embodiments. In the drawings:

[0067] Figure 1 The illustrations depict the normal and pathological processes of intracranial pressure changes over time.

[0068] Figure 2 The basic components of the measuring device of the present invention are schematically shown;

[0069] Figure 3 This illustration schematically shows another embodiment of the retainer configured as a kit;

[0070] Figure 4 An embodiment of the retainer with several bending sensors is illustrated schematically;

[0071] Figure 5 This schematically illustrates yet another embodiment of the retainer having multiple bending sensors;

[0072] Figure 6 The schematic diagram shows a top view of the retainer configured as a kit;

[0073] Figure 7 A top view schematically illustrates yet another embodiment of the retainer configured as a kit;

[0074] Figure 8 The illustration shows a similar Figure 6 Examples of the middle kit;

[0075] Figure 9 An embodiment of the headband with an extendable strap is illustrated schematically;

[0076] Figure 10 An embodiment of the headband with a stretchable elastic band is illustrated schematically;

[0077] Figure 11 Another embodiment of the headband is illustrated schematically;

[0078] Figure 12 The diagram illustrates a measuring device without a headband or straps.

[0079] Figure 13 The diagram illustrates a measuring device with a headband.

[0080] Figures 14a to 14e Different versions of the C-shaped support are illustrated schematically;

[0081] Figure 15 A schematic cross-sectional view of a bending sensor placed on the skull is shown.

[0082] Figure 16 A schematic cross-sectional view of a bending sensor placed on the skull is shown.

[0083] Figure 17 A schematic top view of a bending sensor placed on the skull is shown.

[0084] Figure 18 Schematic illustration Figure 17 The right view of the retainer shown;

[0085] Figure 19 Schematic illustration Figure 17 Left view of the retainer shown. Detailed Implementation

[0086] Figure 1 The left side qualitatively illustrates the normal process of intracranial pressure. Figure 1 The right side illustrates the pathological process of intracranial pressure. Time is plotted on the horizontal axis, while the voltage detected by the sensor is plotted on the vertical axis. Intracranial pressure can be determined based on the waveform of the voltage-time signal. In this regard, characteristic values ​​include, for example, the rise quotient (U1-U0) / t0, i.e., the number of peaks per cardiac cycle, typically 3 to 6. Assessment can also be based on the distance between the respective peaks of at least one pulsation signal and QRS component recorded in parallel via electrocardiogram, or on external arterial pulsation signals acquired at the head, neck, arm, or fingers. For assessment, correlation or correction with the patient's pulse rate or respiratory rate can also be performed.

[0087] Through continuous recording, intracranial pressure (ICP) is shown to be a multi-peak pulse synchronous periodic process: the first peak P is caused by aortic pressure fluctuations; the second peak T is caused by cerebral artery congestion, depending on intracranial compliance; the third peak or even several other peaks are related to diastolic pulsation, for example, aortic valve closure.

[0088] As ICP increases, the T-relative to P and the total pulse pressure amplitude also increase, so the curve shape becomes increasingly similar to a pyramid shape. Therefore, it is possible to infer the static increase in intracranial pressure from the dynamic process.

[0089] The mean static intracranial pressure (ICP) can be indirectly determined from the pulsating waveform by detecting the displacement of a double-layered piezoelectric bending sensor attached to a headband, head strap, or head support surface caused by the pulsating intracranial volume expansion due to intracranial pressure pulsations of approximately 3-4 mmHg. To improve the accuracy of this process, an absolute blood pressure value can be introduced.

[0090] Reference Figure 2 This describes the basic components of the measuring device or the steps of the measuring process. A retainer 2 is attached to the human head 1 and configured as a headband or headband. A piezoelectric bending sensor 3 is located on the headband, detachably arranged on the outside of the human head 1. An accumulator is associated with the bending sensor 3 in the form of an energy storage element 4. Furthermore, the measuring device includes an analog signal amplifier 5 and an analog filter, followed by an A / D converter 6 that converts the analog signal into digital data. The digital data is filtered, smoothed, and reduced in a filter 7. The measuring device further includes an interface 8 for transmitting signals or data. The signals or data can be transmitted to, for example, an external device, a computing unit, or an evaluation unit. The data is used to determine feature values ​​stored in a feature value memory 9. An evaluation unit 10 evaluates the data or feature values. A display 11 is used to output measurement data and other information, including recorded measurement values, signals, feature values, evaluations, or warnings. A structure acoustic sensor 12 is also attached to the retainer 2 to detect interference signals. This eliminates interference signals from external signal sources. The measuring device also includes a preload generator 13. A preload force can be generated by the preload generator 13 and applied to the bending sensor 3.

[0091] Figure 3 The retainer 2 configured as a kit is shown in addition to Figure 2 The illustrated assembly also includes embodiments of two additional bending sensors 14 and 15. The bending sensor 3, arranged in the head, further comprises... Figure 2 The components shown include, for example, energy storage devices, analog signal amplifiers, and A / D converters.

[0092] Figure 4 and Figure 5An embodiment is further shown in which the retainer has multiple bending sensors, which are temporarily fixed to the patient’s skull by applying a preload force to the bending sensors.

[0093] Figure 6 A schematic top view shows a retainer configured as a headband 16 and attached to the skull. The headband 16 has several spaced-apart pads 17 on its inner side, each pad forming a contact surface with the skull. There may be gaps between adjacent pads 17, or alternatively, the gaps may be filled with sponge. A bending sensor is arranged on the outer side of the headband 16. The headband 16 also includes a preload generator 13 and an extension member 18 formed as an elastic band. An extension limiter 19 restricts the extension. The headband 16 also includes hook-and-loop fasteners 20 for securing the free end of the headband 16.

[0094] In an alternative embodiment, the headband may be provided with viscoelastic memory foam, which has the property of hardening under high-speed loading, especially under high-speed impact.

[0095] Figure 7 Another embodiment of the retainer configuration as a headband 21 is shown. The headband 21 is made of an elastic material, i.e., a stretchable material. According to the aforementioned embodiment, the headband 21 has a hook-and-loop fastener 20 and an elongation limiter 19. A viscoelastic memory foam 22 serves as a pad on the inner side of the headband 21. A total of four bending sensors 3 are distributed around the periphery on the outer side of the headband 21. Each bending sensor 3 is mounted on a flexible pad 23. Furthermore, a structural acoustic sensor 12 is arranged on the outer side of the headband 21.

[0096] Figure 8 Similar Figure 6 The headband 16 shown is an embodiment. In addition to the gasket 17 forming the contact surface and the bending sensor 3, the headband also has an air cushion 24 that can be inflated by a manual pump 25.

[0097] The embodiments described all show a closed headband extending along the entire periphery of the patient's skull. However, the headband may also extend and clamp only along a portion of the periphery of the skull. For this purpose, the headband may be made of a flexible material, a bendable material, or a spring-elastic material.

[0098] Figure 9 An embodiment of the headband is shown, featuring a stretchable elastic band 27 extending around the entire periphery of the skull. The elastic band 27 has multiple bending sensors 3 on its outer side, which are attached to the patient's skull via flexible bending elements 28 with pads. The elastic band 27 also has an elongation limiter 19.

[0099] In the modified embodiment, a non-stretchable tension band can be used instead of a stretchable elastic band. In this case, a shorter stretchable element is needed to attach the headband to the skull with a certain preload.

[0100] Figure 10 An embodiment of a headband 29 is shown, comprising a stretchable elastic band 27 and multiple bending sensors 3, each bending sensor being disposed on the outer side of a C-shaped support 30. The C-shaped support 30 includes a middle section and two distal sections extending vertically from the middle section. The distal sections of the C-shaped support 30 face the skull. The C-shaped support 30 is flexibly bendable and is circumferentially positioned on the patient's skull to cover the cranial sutures. Elongation of the skull due to pulsation can be detected by the bending sensors 3.

[0101] Figure 11 Similar Figure 10 An embodiment of the headband 31 shown. A total of four C-shaped supports 30 are arranged on the headband 31, with their ends facing away from the skull passage. A bending sensor 3 is located on the outside of each C-shaped support 30.

[0102] Figure 12 An embodiment of the measuring device is shown, in which the retainer is configured as a flexible bending member 32. Bending sensors 3 are arranged on the outside of the flexible bending member 32. A total of four such bending sensors 3 are present around the periphery of the skull. The flexible bending member 32 is bonded to the skull; in this embodiment, no fitting or strap is required.

[0103] Figure 13 A measuring device is shown, comprising a headband 33, a C-shaped support 30, and a piezoelectric bending sensor 3. A pad 34 made of sponge is located inside the headband 33. On the opposite side of the piezoelectric bending sensor, a preload generator 13 generates a preload using an adjusting screw 35. The preload generator 13 includes an indicator 36 for indicating the preload.

[0104] Figures 14a to 14e Various embodiments of the C-shaped support are shown.

[0105] from Figure 14a As can be seen, the C-shaped support 30 is positioned on the outer surface 37 of the patient's skull with its distal end. The bending sensor 3 is located inside the C-shaped support 30, which is positioned across the cranial suture 38. The strap 39 is used to secure the C-shaped support 30 in place. The strap 39 can be rigid, flexible, bendable, or stretchable.

[0106] Figure 14b It is similar Figure 14a The view shows an elastic pad 40 disposed between the outer surface 37 of the skull and the C-shaped support 30.

[0107] Figure 14c It is similar Figure 14b The view shows the bending sensor 3 located outside the C-shaped support 30.

[0108] Figure 14dAn embodiment is shown in which the C-shaped support 30 rests on the outer surface 37 of the skull at its middle section. Thus, the distal section of the C-shaped support 30 protrudes from the outer surface 37 of the skull. A bending sensor 3 is located on the outside of the C-shaped support 30, held by a strap 39. Optionally, an elastic pad may be arranged between the outer surface 37 of the skull and the C-shaped support 30.

[0109] Figure 14e An embodiment is shown in which a bending sensor 3 is integrated into a support 30. The bending sensor is located within the middle section of the support 30, which can be attached to any location on the outer surface 37 of the patient's skull, but with the artery bridged in the process. A pad 34 is located between the skull and the angled distal segment, and preload can be introduced by a strap or strip 39 attached to either side of the distal segment of the C-shaped support.

[0110] Figure 15 A cross-sectional view of a double-layered piezoelectric bending sensor 3 placed on the outer surface 37 of the skull is shown for illustration. A strap 39 is used to generate preload. One end of the bending sensor 3 is placed on a cranial suture, such as a coronal suture, sagittal suture, or lambdoid suture.

[0111] Figure 16 A cross-sectional view of the double-laminated piezoelectric bending sensor 3 is shown, with its centrally located lower outward-curving protrusion 42 resting on a rigid support 41. The support 41 covers the cranial sutures. A prestress is generated by the strap 39 acting on the bending sensor 3. The protrusion 42 supports the bending sensor 3 in a rocker-like manner, and changes in skull volume can be transmitted to the sensor through the strap, causing the sensor to bend and detect the change.

[0112] Figure 17 This is a top view showing a retainer arranged on the skull. Figure 18 It shows Figure 17 The retainer shown has a C-shaped support on the right side. Figure 19 It shows Figure 17 The retainer shown has a locking mechanism on the left side, which can be used to generate a preload.

[0113] from Figures 17 to 19 As can be seen, the C-shaped support 30 of the retainer is positioned at its distal end on the lateral side of the patient's skull. A double-layered bending sensor is located inside the C-shaped support, symmetrical about the neutral fibers in the middle section of the support, which is attached to the skull to bridge the external carotid artery. A strap is used to transmit the volume deviation of the skull caused by intracranial pressure pulsations to the bending point of the C-shaped support. This retainer's strap is rigid in the traction direction, flexible in the bending direction, and padded in the direction towards the skull. On the opposite left side are a locking mechanism for adjusting the preload and an indicator for indicating the preload. The locking mechanism is also C-shaped, bridging the external carotid artery to avoid interference from it.

[0114] This arrangement can also be used to measure blood pressure pulsations, thereby measuring blood pressure in the head, by selectively mechanically coupling the band or pad to one or more arteries (e.g., the carotid artery). In this configuration, the external blood pressure pulsation signal is significantly stronger than the skull displacement signal caused by intracranial pulsations. This “instantaneous” coupling can be achieved by rotating the headband (i.e., the band) 90 degrees so that the carotid artery is below the band’s bearing surface. However, this coupling can also be achieved without rotation by inserting a sponge under the locking mechanism and / or the C-shaped support. Advantageously, the headband, formed as a band, includes a coupling element reversibly coupled to the carotid artery at the location of the C-shaped support and / or the locking mechanism. Coupling can also be achieved, for example, by a threaded or folding coupling mechanism similar to a quick-acting switch. The coupling force can be adjusted using existing locking mechanisms, preferably adjusted to the system calibration value.

[0115] The features of the above-mentioned measuring equipment and related methods can be combined in any way.

[0116] Figure Labels

[0117] 1. Head

[0118] 2. Holder

[0119] 3. Bending sensor

[0120] 4. Energy storage components

[0121] 5. Analog signal amplifier

[0122] 6 A / D converter

[0123] 7 Filters

[0124] 8 interfaces

[0125] 9. Eigenvalue Memory

[0126] 10 assessment units

[0127] 11 monitors

[0128] 12 structural acoustic sensors

[0129] 13 Preload Generator

[0130] 14 Bending Sensors

[0131] 15 Bending Sensors

[0132] 16 headbands

[0133] 17 gaskets

[0134] 18 elongated pieces

[0135] 19 Elongation Limiter

[0136] 20 hook and loop fasteners

[0137] 21 headbands

[0138] 22 memory foam

[0139] 23 Flexible gasket

[0140] 24 Air Cushion

[0141] 25 pumps

[0142] 26 headbands

[0143] 27 elastic bands

[0144] 28 Flexible bending parts

[0145] 29 headbands

[0146] 30C-shaped support

[0147] 31 headbands

[0148] 32 Flexible bending parts

[0149] 33 headbands

[0150] 34 gasket

[0151] 35 Adjustment Screw

[0152] 36 monitors

[0153] 37 outer surface

[0154] 38 cranial sutures

[0155] 39 straps

[0156] 40 gasket

[0157] 41 supports

[0158] 42 protrusions

Claims

1. A measuring device for non-invasive detection of intracranial pressure pulsation in a patient, comprising: The retainer (2) is detachably attached to the outside of the patient’s skull in a force-fit and / or shape-fit manner; At least one double-layered bending sensor (3, 14, 15) has two antiparallel polarity bending sensor layers arranged symmetrically around a neutral fiber and arranged in or on the retainer (2), wherein, after bending in one direction, one of the bending sensor layers extends while the other bending sensor layer is equally compressed, and the bending sensor layers have signals superimposed when loaded in opposite directions. An analog signal amplifier (5) is used to amplify the measurement data provided by the double-layer bending sensor (3, 14, 15); A / D converter (6) is used to convert analog measurement data into digital data; The calculation unit is used to preprocess the data and calculate the parameters related to vital state variables in the intracranial pressure pulsation curve based on the digital data.

2. The measuring device according to claim 1, wherein, The retainer (2) is formed as a headband or headband and / or has a display (11) for displaying measurement curves, calculated parameters and associated time histories.

3. The measuring device according to claim 1, wherein, The double-layered bending sensors (3, 14, 15) are double-layered piezoelectric bending sensors.

4. The measuring device according to claim 1, wherein, The dual-layer bending sensors (3, 14, 15) are arranged in a rocker-like manner on a support that can be attached to the outside of the patient's skull and can move around a pivot point.

5. The measuring device according to claim 1, wherein, The double-layered bending sensors (3, 14, 15) are arranged in the middle section between the two end sections of the C-shaped support (30).

6. The measuring device according to claim 2, wherein, When the retainer (2) is configured as a headband, it has a preload generator (13) for generating and adjusting the preload acting on the patient’s skull.

7. The measuring device according to claim 6, wherein, The preload generator (13) has a force sensor or a strain sensor.

8. The measuring device according to claim 6, wherein, The preload generator (13) includes an indicator for the preload or its associated voltage.

9. The measuring device according to claim 6, wherein, The preload generator (13) is configured to automatically set a predetermined preload.

10. The measuring device according to claim 9, wherein, The preload generator (13) includes an electromechanical or pneumatic mechanism.

11. The measuring device according to claim 2, wherein, When the retainer (2) is configured as a headband, it has pads (17, 40) over at least a portion of its length.

12. The measuring device according to any one of claims 1 to 11, wherein, The measuring device includes one or more of the following sensors: a structure acoustic sensor (12), an acceleration sensor, a position sensor, an external pulsation sensor, an external blood pressure sensor, and a temperature sensor, wherein the computing unit is configured to detect external interference effects or conditions detected by at least one of the sensors and correct the interference effects if necessary.

13. The measuring device according to claim 2, wherein, When the retainer (2) is formed into a headband, the double-layered bending sensor (3, 14, 15) can be removed and replaced therefrom.

14. The measuring device according to any one of claims 1 to 11, wherein, The measuring device includes a data logger connected to the A / D converter (6) or the computing unit.

15. The measuring device according to claim 2, wherein, When the retainer (2) is configured as a headband, it includes an energy storage device (4).

16. The measuring device according to claim 15, wherein, The energy storage device (4) includes a battery.

17. The measuring device according to claim 16, wherein, The energy storage device (4) includes a rechargeable battery.

18. The measuring device according to any one of claims 15 to 17, wherein, The double-layer bending sensor (3, 14, 15) and / or the analog signal amplifier (5) and / or the A / D converter (6) are connected to the transmitter.

19. The measuring device according to claim 18, wherein, The dual-layer bending sensor (3, 14, 15) and / or the analog signal amplifier (5) and / or the A / D converter (6) are connected to the wireless data transmission transceiver.

20. The measuring device according to claim 18, wherein, The dual-layer bending sensor (3, 14, 15), the analog signal amplifier (5), the A / D converter (6), and / or if any, the transmitter and / or if any, the energy storage device are integrated into a single component.

21. The measuring device according to claim 2, wherein, When the retainer (2) is configured as a headband, it is equipped with multiple piezoelectric bending sensors.

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