Circuit arrangement for biomedical interface

Abstract

A circuit arrangement for a biomedical interface is described, the circuit arrangement having electrical contacts, n of the electrical contacts for contacting with at least one implantable electrode arrangement, the at least one implantable electrode arrangement being attachable to an organic structure; the circuit arrangement has at least one electrical functional block, which is electrically connected to at least one of the n electrical contacts. The invention is characterized in that the at least one electrical functional block has functional elements implemented by means of SOI technology, and in that the at least one electrical functional block can be operated at a supply voltage to which a level average potential can be assigned, said supply voltage corresponding to a potential that can be assigned to the organic structure.

Description

Technical Field

[0001] The present invention relates to a circuit device for a biomedical interface, the circuit device having electrical contacts, n of the electrical contacts being for contacting at least one implantable electrode device capable of being attached to an organic structure; and the circuit device having at least one electrical functional block electrically connected to at least one of the n electrical contacts. Background Technology

[0002] Functional electrical stimulation or nerve stimulation (FES / FNS) is a method of treating various types of neurological dysfunctions by stimulating nerves with electrical charges. Applications range from cardiac pacemakers and retinal implants to peripheral nerve stimulators.

[0003] Implantable electronic devices designed for use in FES / FNS typically contain different functional switching regions called functional blocks (FBs), which are used for, for example, energy management, monitoring and / or control, data storage, charge balancing, voltage conversion (level shifters), and detection of neural signals and active stimulation, to name just a few examples of FBs.

[0004] The paper “A Charge Balanced Neural Stimulator with 3.3V to 49V Supply Compliance and Arbitrary Programmable Current Pulse Shapes” by A. Taschwer et al., 2018 IEEE Biomedical Circuits and Systems Conference (BioCAS), Cleveland, OH, USA, 2018, pp. 1-4, doi:10.1109 / BIOCAS.2018.8584755, explains the circuit concepts related to the design and operation of neurostimulators.

[0005] Functional blocks for detecting neural signals and stimulation are directly electrically connected to the organic structure via at least one electrode or electrode device individually matched to the organic structure. A known implantable electrode device is disclosed in document EP 3 204 105 B1 for site-selective recording of neural electrical signals propagating along at least one nerve fiber, and for selective stimulation of at least one nerve fiber.

[0006] The most important requirement for all neurostimulators is patient safety; that is, the level of electrical stimulation applied to at least one organic structure must be organically tolerable, and reliable measures must be taken to protect the patient even in the event of a malfunction within the inherent circuitry of the implantable electronic device.

[0007] Document DE 19951491 A1 discloses a medical device comprising a first digital signal processing system that receives at least one first analog input. The first digital signal processing system has a first digital signal processor that processes data representing at least the first analog input at a first clock frequency to perform at least one first function within a specified time period. Furthermore, a second digital signal processing system is envisioned that receives at least one second analog input. The second digital signal processing system has a second digital signal processor that processes data representing at least the second analog input at a second clock frequency to perform at least one second function within a specified time period. The corresponding first and second digital processing systems are constructed from circuits selected from the group consisting of CMOS circuits, CML circuits, SOS circuits, SOI circuits, BICMOS circuits, PMOS circuits, and NMOS circuits.

[0008] Document US2014 / 0200626 A1 discloses an implantable transient neurostimulation device for stimulating target tissue in a patient, wherein the device includes a substrate configured to wirelessly communicate with a controller disposed outside the patient and configured to stimulate the target tissue. The substrate and circuitry are surrounded by a material configured to degrade within the patient.

[0009] Document EP 2 446 921 B1 describes a circuit for selecting a number of electrodes in an implantable electrode device, wherein the circuit includes a signal interface having multiple electrodes and signal connections, and a switching electronics having a programmable switch, wherein the switch is designed as a MOS transistor with charge storage. Summary of the Invention

[0010] The present invention is based on the objective of further developing a circuit device for a biomedical interface, the circuit device having electrical contacts, n of which are for contacting at least one implantable electrode device capable of being attached to an organic structure; and the circuit device having at least one electrical functional block electrically connected to at least one of the n contacts, thereby avoiding or at least significantly reducing the risk to the patient in the event of a possible malfunction during operation of a medical active implant including the circuit device.

[0011] The solution to the task upon which this invention is based is set forth in claim 1. Advantageous further developments of the inventive concept form the subject matter of the dependent claims and can be found in the further description, particularly with reference to the accompanying drawings.

[0012] According to the solution, a circuit device for a biomedical interface having the features described in the preamble of claim 1 is characterized in that the at least one electrical functional block has functional elements implemented by means of SOI technology (i.e., "silicon-on-insulator" technology), and in that the at least one electrical functional block is operable at a supply voltage, and an average electrical potential can be distributed to the supply voltage, the supply voltage corresponding to a potential that can be distributed to the organic structure.

[0013] Each of the n electrical contacts, directly or indirectly connected to the organic structure for stimulating and / or detecting neural signals or similar purposes, is also connected to at least one electrical functional block of the circuit device, which is part of an implantable medical device (e.g., in the form of a neurostimulator). Each individual electrical functional block (e.g., necessary for measuring and detecting neural signals, generating stimulation signals, or controlling single or all functional blocks) is individually configured for a different supply voltage, which in conventional circuit devices (i.e., by means of bulk CMOS semiconductor technology) is simply a positive voltage potential. Combining or interconnecting these individual supply voltages to a common circuit output or input, especially in the event of a fault, can lead to surges and destructive effects.

[0014] The circuit arrangement according to this solution leverages the advantages of SOI technology, where circuit elements are dielectrically insulated, thereby reducing excess capacitance and enabling high-speed switching operation with lower power at the same switching speed as conventional circuit arrangements. More specifically, SOI technology allows the use of both positive and negative supply potentials, thus allowing individual electrical functional blocks to operate not only using positive voltages (including zero volts), but also using supply voltages whose voltage ranges are defined by the lowest negative voltage value and the highest positive voltage value, respectively. This provides the possibility of selecting an average potential characterized by having the smallest possible voltage value (i.e., slightly off-zero volts or zero volts). Preferably, the average potential of all electrical functional blocks in the circuit arrangement is selected to be the same.

[0015] Since the circuitry is part of a medical and / or functional implant, preferably an active medical implant, and the electrical contacts of the circuitry are connected to the endogenous organic structure via appropriately assembled electrodes, the average potential of the supply voltage for all electrical functional blocks is selected according to the body's organic potential. In this way, it is ensured that no electrical load or stimulation acts on the organic structure in the event of a fault within the circuitry or the need for a switching process.

[0016] To provide power to all electrical functional blocks of a circuit device preferably configured as an ASIC circuit, a voltage source in the form of a floating voltage source is used. This floating voltage source is either designed as an integral component, thus part of the circuit device, or as a separate component, connected to the circuit device via at least one electrical contact. Regardless of the arrangement and design of the voltage source relative to the circuit device, it must be arranged separately from all organic structures in terms of current.

[0017] Depending on the type and function of the medical active implant, the circuitry must be assembled and fitted with the necessary electrical functional blocks, the functions of which can be assigned to correspond to one of the following functional possibilities:

[0018] - Generate stimulation signals controlled by voltage or current.

[0019] - Detect biomarkers, especially electrobiological signals;

[0020] -Voltmeter-ammeter method, Ampere method;

[0021] -Control electromechanical components

[0022] - Energy harvesting using piezoelectric, thermoelectric, and / or electrochemical transducer elements;

[0023] - Measuring and monitoring supply voltage

[0024] - Electrically connect at least two functional blocks.

[0025] - Signal output is used for external signal processing.

[0026] The structure and arrangement of each functional block use only components implemented with SOI technology, preferably in the form of CMOS transistors or optical components. Attached Figure Description

[0027] The invention will now be described with reference to the accompanying drawings and examples of embodiments, without limiting the overall inventive concept. In the drawings:

[0028] Figure 1 A block diagram of an implantable circuit device for controlling neurostimulation electrodes is shown, and

[0029] Figure 2 The power supply voltages for different electrical functional blocks are shown. Detailed Implementation

[0030] Figure 1 A schematic block diagram of a circuit device 2 designed for an active medical implant 1, for example, for vagus nerve stimulation, is shown.

[0031] The electrical switching device 2 is implemented on the chip 3 in the form of an application-specific integrated circuit (ASIC), i.e., implemented as an ASIC chip. The electrical switching device 2 has multiple different electrical functional blocks F1, F2, F3, ... Fn. These electrical functional blocks are entirely composed of functional elements implemented using SOI technology, preferably in the form of CMOS transistors or optical components. Depending on the type and function of the medical implant, the selection and arrangement of the different electrical functional blocks F1, ... Fn, as well as the interconnection of these electrical functional blocks on the chip 3, must be appropriately coordinated.

[0032] The circuit device 2 has electrical contacts 4, n of which are used to contact at least one implantable electrode device 6, which can be attached to the organic structure 5. Figure 1 In the example shown, it is assumed that the electrode device 6 is designed as a wrap-around or sleeve-type electrode device and is attached around the vagus nerve, which is an organic structure 5. For example, this type of electrode device 6 designed as a wrap-around device is disclosed in document EP 3 204 105 B1. The n electrical contacts 4 are connected to the electrode device 6 via conductor devices 7.

[0033] Meanwhile, n electrical contacts 4 of the circuit device 2 are connected to at least one of the electrical functional blocks F1, F2, ..., Fn, and the electrical functional blocks are interconnected according to a predefined circuit diagram.

[0034] The n electrical contacts 4 connected to at least one electrical functional block F1, ..., Fn and at least one electrode 6' of the electrode device 6 are respectively configured to adapt to the maximum supply voltage of the electrical functional blocks F1, ..., Fn attached to the chip 2. Each of the n electrical contacts 4 is capable of contacting one or more electrical functional blocks of the chip 3.

[0035] For example, an electrical energy source, preferably designed as a floating voltage source, and a functional block (e.g., F1) configured for voltage monitoring can be connected to the same electrical contact or contact pair 4, on which a maximum supply voltage of ±18 volts can be acquired or applied. On another electrical contact 4 or contact pair, an electrical functional block (e.g., F2) used as a precision measurement circuit can be connected, operating with a supply voltage of ±0.9 volts. Correspondingly, various different supply voltages matching the function of the electrical functional block Fn can also be applied to corresponding other contacts 4. All different supply voltages share a common reference potential or average potential M, which, in the above example, is selected as 0V.

[0036] exist Figure 2 The voltage diagram shown illustrates the supply voltages for electrical functional blocks F1, F2, and F3. Clearly, all electrical functional blocks, regardless of their specifications, have the same average potential M, which preferably corresponds to the organic resting potential.

[0037] In this way, various simultaneous combinations and new interconnections can be achieved between the various electrical functional blocks F1, F2, ... Fn and the electrical contact 4, especially when the chip 3 is in a resting state, the same reference potential or average potential (0 volts in this case) is always applied to the electrical contact 4 and thus to the electrode 6' which is in contact with the organic structure 5. Of course, the average potential M can also be set to a value deviating from 0 volts according to the organic potential to which the electrode 6' is connected.

[0038] In this way, different potentials can be prevented from occurring on the electrical contact 4, which would cause direct current between the various contact 4s.

[0039] Since different resting potentials do not exist between electrical contacts, a constant direct current is avoided. Furthermore, even with functional re-interconnection, the potential at the electrode contacts does not change rapidly. Additionally, destructive effects at individual electrical functional block nodes can be reduced, and the so-called latch-up effect can be completely eliminated.

[0040] List of reference numerals

[0041] 1. Medical implants

[0042] 2. Circuit device

[0043] 3 chips

[0044] 4 Electrical contact parts

[0045] 5. Organic Structure

[0046] 6. Electrode device, sleeve electrode

[0047] 6' electrode

[0048] 7 Conductor apparatus

Claims

1. A circuit device for a biomedical interface, the circuit device having electrical contacts, n of the electrical contacts being configured to contact at least one implantable electrode device, the at least one implantable electrode device being attachable to an organic structure; and the circuit device having at least one electrical functional block electrically connected to at least one of the n electrical contacts, characterized in that, The at least one electrical functional block has functional elements implemented using SOI technology, and The at least one electrical functional block is capable of operating at a supply voltage, and an average electrical potential can be distributed to the supply voltage, which corresponds to a potential that can be distributed to the organic structure.

2. The circuit device according to claim 1, Its features are, The circuit device is designed to be in the form of an integrated circuit, particularly in the form of an ASIC circuit.

3. The circuit device according to claim 1 or 2, Its features are, The circuitry is part of a medical implant and / or a functional implant.

4. The circuit device according to claim 3, Its features are, The medical implant is an active medical implant.

5. The circuit device according to claim 4, Its features are, The active medical implant is used for nerve stimulation or nerve modulation.

6. The circuit device according to any one of claims 1 to 5, Its features are, The supply voltage comes from a voltage source designed as a floating voltage source, which is arranged and configured to be electrically isolated from the organic structure.

7. The circuit device according to claim 6, Its features are, The voltage source is designed and arranged as an integral part of the circuit device.

8. The circuit device according to claim 6, Its features are, The voltage source is designed as a component separate from the circuit device, and the voltage source is connected to the circuit device via at least one of the electrical contacts.

9. The circuit device according to any one of claims 1 to 8, Its features are, At least one of the following functions can be assigned to the at least one electrical function block: - Generate stimulation signals controlled by voltage or current; - Detect biomarkers, especially electrobiological signals; -Voltmeter-ammeter method, Ampere method; -Control electromechanical components - Energy harvesting using piezoelectric, thermoelectric, and / or electrochemical transducer elements; -Measure and monitor the supply voltage, - Electrically connect at least two functional blocks. - Signal output is used for external signal processing.

10. The circuit device according to any one of claims 1 to 9, Its features are, The functional element realized by means of SOI technology is at least one of the following components: transistor, optical component.

11. The circuit device according to any one of claims 1 to 10, Its features are, The electrodes that can be attached to the organic structure are part of a sleeve electrode device, and The key is that the vagus nerve's organic structure is that of a living organism.

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