Extensible three-dimensional electrical impedance imaging electrode array device
By using a series-parallel structure of a two-dimensional electrode interface module, a three-dimensional shared electrode array, and a three-dimensional electrode control module, the problem that two-dimensional electrode arrays cannot perform three-dimensional measurements is solved, achieving compatible, flexible expansion, and high-precision three-dimensional electrical impedance imaging.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- GUILIN UNIV OF ELECTRONIC TECH
- Filing Date
- 2026-03-17
- Publication Date
- 2026-04-24
AI Technical Summary
Existing two-dimensional electrode arrays cannot perform three-dimensional measurements. Dedicated three-dimensional electrode systems are complex in structure, expensive, incompatible with existing two-dimensional devices, and have poor scalability.
It employs a two-dimensional electrode interface module, a three-dimensional shared electrode array, and a three-dimensional electrode control module. Through analog switch units with series and parallel structures, it achieves flexible expansion of the number of electrodes and layers. Combined with isolated analog switch units, it suppresses signal crosstalk and is compatible with existing two-dimensional equipment.
It achieves compatibility and flexible expansion of 3D measurement, reduces costs, improves measurement accuracy and data acquisition density, and lowers the technical threshold.
Smart Images
Figure CN121910355A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of biomedical measurement technology, and in particular to an electrode array device for three-dimensional electrical impedance imaging. Background Technology
[0002] Electrical impedance imaging (EIA) is a non-invasive, radiation-free functional imaging technique. Currently, most commercial EIA devices use two-dimensional planar electrode arrays, which can only acquire two-dimensional impedance information of the measured object and cannot reconstruct the three-dimensional impedance distribution. Although dedicated three-dimensional electrode systems exist, they are usually complex in structure, expensive, and incompatible with existing two-dimensional devices. In addition, traditional three-dimensional electrode arrays have a fixed number of electrodes and layers, poor scalability, and are difficult to adapt to different measurement needs. Summary of the Invention
[0003] The purpose of this invention is to provide a scalable three-dimensional electrical impedance tomography electrode array device to solve the problems that existing two-dimensional electrodes cannot perform three-dimensional measurements, while dedicated three-dimensional electrode systems are not compatible with existing two-dimensional devices and have poor scalability.
[0004] To achieve the above objectives, the present invention adopts the following technical solution:
[0005] A scalable three-dimensional electrical impedance imaging electrode array device, characterized in that it comprises:
[0006] A two-dimensional electrode interface module is used to connect to the electrode output terminal of the original two-dimensional impedance measurement equipment. It includes multiple sets of two-dimensional electrode interface units. Each set of two-dimensional electrode interface units includes a two-dimensional electrode input interface for connecting to the electrode output of the original equipment and a two-dimensional electrode expansion interface for connecting to a lower-level similar device. The two-dimensional electrode input interface and the two-dimensional electrode expansion interface are connected in series.
[0007] A three-dimensional shared electrode array for contacting the object under test includes multiple rows of measuring electrodes, each row containing multiple independent electrodes from different horizontal electrode array layers.
[0008] A three-dimensional electrode control module, the input of which is connected to the output of the two-dimensional electrode interface module, and the output of which is connected to the three-dimensional common electrode array, the three-dimensional electrode control module comprising:
[0009] The parallel electrode array control connector includes a control input interface and a control expansion interface, wherein the control input interface and the control expansion interface are connected in parallel and their corresponding control ports are electrically connected.
[0010] An isolated analog switch unit includes multiple series-connected analog switches configured to electrically isolate the horizontal electrode channels and the vertical electrode layers from each other. The signal input terminal of the isolated analog switch unit is connected to the two-dimensional electrode input interface, its signal output terminal is connected to the three-dimensional common electrode array, and its control terminal is connected to the control input interface.
[0011] The isolated analog switch unit includes multiple sets of analog switch groups. Each set of analog switch groups consists of multiple series-connected analog switch units, which are used to control the switching on and off of multiple electrode signal channels from different horizontal planes in the vertical direction.
[0012] Among them, the control terminals of all analog switch groups responsible for the signal channels at the same horizontal level are interconnected and lead to an independent control port of the control input interface;
[0013] The isolated analog switch unit is configured to: respond to a control signal sent through a control port of the control input interface, uniformly control the on / off state of all electrode channels in the three-dimensional shared electrode array corresponding to a certain horizontal level.
[0014] The multiple sets of analog switches in the isolated analog switch unit are isolated from each other to achieve isolation between different signal channels in the horizontal direction;
[0015] Furthermore, the multi-stage series analog switch units in each group of analog switches, through their cascaded turn-off capacitors, collectively increase the impedance of the channel in the off state, thereby achieving vertical isolation of non-gated horizontal plane signals.
[0016] Each column of measuring electrodes in the three-dimensional common electrode array has multiple independent electrodes that are respectively connected to different signal channels of the analog switch unit in the same group of analog switches that is directly electrically connected to the three-dimensional common electrode array.
[0017] The parallel structure of the control input interface and the control expansion interface is configured such that when the control expansion interface of this device is connected to the control input interface of another similar device, the control signal input to the control input interface of any device can synchronously control the isolated analog switch units of all connected devices, thereby synchronously controlling the on / off state of the electrode channels on the same horizontal level in all devices, and realizing the expansion of the number of electrodes in the horizontal direction.
[0018] The series structure of the two-dimensional electrode input interface and the two-dimensional electrode expansion interface is configured such that: when the two-dimensional electrode expansion interface of this device is connected to the two-dimensional electrode input interface of another similar device, if the isolated analog switch unit of this device is in the on state, the electrode output signal of the original device is transmitted through the two-dimensional electrode input interface, the isolated analog switch unit and the three-dimensional shared electrode array of this device; if the isolated analog switch unit of this device is in the off state, the electrode output signal of the original device is transmitted to the two-dimensional electrode input interface of the lower-level device through the two-dimensional electrode expansion interface, thereby realizing the vertical expansion of the electrode array layer.
[0019] Compared with the prior art, the present invention has the following beneficial effects:
[0020] 1. Strong compatibility: No modification is required to the original two-dimensional electrical impedance measurement equipment hardware. It can be upgraded to a three-dimensional measurement system through the standard two-dimensional electrode interface, protecting the user's original investment.
[0021] 2. Flexible expansion: Supports expansion of the number of electrodes and layers in both horizontal and vertical directions. Users can flexibly configure the system scale according to measurement needs, resulting in high data acquisition density.
[0022] 3. Good signal isolation: It adopts a unique "multi-group multi-level series analog switch unit" structure, and uses cascaded turn-off capacitors to increase the turn-off impedance, which effectively suppresses signal crosstalk between horizontal channels and between vertical layers, ensuring measurement accuracy.
[0023] 4. Low cost and easy to promote: As an independent extension accessory, this device directly utilizes the user's existing 2D equipment, eliminating the need to purchase a dedicated 3D host, significantly reducing hardware costs. Furthermore, its plug-and-play feature greatly lowers the technical barrier for users upgrading from 2D measurement to 3D imaging, facilitating technology popularization. Attached Figure Description
[0024] Figure 1 This is a block diagram of the overall system structure of the present invention. Detailed Implementation
[0025] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby providing a clearer and more explicit definition of the scope of protection of the present invention.
[0026] Before describing the specific embodiments of the present invention, it is necessary to explain the connection relationship between the device and the external system to ensure the completeness and feasibility of the technical solution:
[0027] refer to Figure 1The device of the present invention is an independent module that connects to the electrode output terminal of the original two-dimensional electrical impedance measurement device through its two-dimensional electrode interface module, contacts the object under test through its three-dimensional common electrode array, and receives instructions from an external controller through its three-dimensional electrode control module. Figure 1 The connection between these three core modules and external devices is clearly shown, including the external controller, the two-dimensional electrode interface module (containing N serial input interfaces), the three-dimensional control module (containing parallel control connectors and N isolated analog switch units), and the three-dimensional electrode array (containing 3 layers and N columns of electrodes), without limiting the specific number of electrodes and layers.
[0028] This embodiment provides a typical scalable three-dimensional electrical impedance imaging electrode array device with a 16-electrode interface and a 3-layer electrode array. The device connects one-to-one with the electrode output ports of the original two-dimensional electrical impedance measurement equipment (such as a certain model of a 16-electrode EIT system) via coaxial cables through its 16 sets of two-dimensional electrode input interfaces. The three-dimensional shared electrode array comprises three horizontal layers in the vertical direction, with 16 electrodes distributed in each layer. In the horizontal direction, the electrodes are grouped in columns of three, with the electrodes within each group originating from three different horizontal layers. The isolated analog switch unit of the three-dimensional electrode control module employs multiple sets of analog switch groups, each consisting of two stages of ADG5412 analog switch chips connected in series. These chips feature low on-resistance and high off-resistance; through the two-stage series connection, the total off-resistance is significantly improved, which is crucial for achieving signal isolation between vertical layers. Specifically, the two-stage ADG5412 employs a series connection: the signal output of the first-stage ADG5412 is connected to the signal input of the second-stage ADG5412, and the control terminals of both stages are connected in parallel to receive the same control signal, achieving synchronous turn-on or turn-off. The reason for choosing a two-stage series connection instead of a single-stage connection is that the typical impedance of a single-stage ADG5412 in the turn-off state is 10 GΩ, while the theoretical turn-off impedance of the two-stage series connection can reach 20 GΩ, thus significantly improving turn-off isolation. Experimental results show that the two-stage series connection reduces inter-channel crosstalk by approximately 40 dB, effectively suppressing signal leakage in the non-gated layer (vertical direction) of the three-dimensional electrode array.
[0029] The following section explains the signal control and path establishment of this device in conjunction with its working process:
[0030] The hierarchical control principle of this invention is as follows: When it is necessary to measure the first layer electrode, the external controller (such as a microcontroller or FPGA) sends a valid on-state level (e.g., a TTL high-level signal) to the "first layer" control port of the control input interface. This control signal is synchronously sent to the control terminals of the switching units responsible for the first layer channels in all analog switch groups through parallel lines, so that they are all turned on, thereby physically connecting the multiple channels of the original device to the first layer electrode of the three-dimensional electrode array.
[0031] At this point, the original equipment operates according to its internally preset measurement sequence.
[0032] Excitation current output path: The original device outputs excitation current through one of its excitation output ports. This current travels through the corresponding coaxial cable, the two-dimensional electrode input interface of this device, and the activated analog switch unit, finally reaching a designated excitation electrode on the first layer of the three-dimensional common electrode array and being injected into the object under test.
[0033] Excitation current return path: The excitation current needs to form a closed loop. After being conducted through the object under test, the current is collected by another electrode (i.e., the excitation return electrode) on the first layer of the three-dimensional shared electrode array. This return electrode corresponds to the excitation return channel port of the original device. The return signal is also returned to the original device via a coaxial cable through the activated analog switch unit and the corresponding two-dimensional electrode input interface.
[0034] Measurement signal path: Simultaneously with the application of excitation or at a specific timing, the original equipment synchronously receives the measurement voltage signal through its measurement port. The measurement voltage signal originates from the surface of the object under test, passes through the measurement electrodes of the first layer of the three-dimensional common electrode array, and is received by the measurement port of the original equipment via the corresponding activated analog switch unit and two-dimensional electrode input interface.
[0035] It is important to emphasize that the specific electrodes used as excitation electrodes, excitation return electrodes, and measurement electrodes are entirely determined by the original equipment's excitation and measurement channel configuration strategy. The core function of this device is to ensure that at any given time, all channels of the original equipment establish a one-to-one signal channel with the electrodes of the same horizontal layer (the first layer in this example) in three-dimensional space, thereby realizing the conversion from two-dimensional planar measurement to three-dimensional layered measurement.
[0036] Extended implementation:
[0037] Horizontal Expansion: When it is necessary to increase the number of electrodes in the horizontal direction, the control expansion interface of the first device can be connected to the control input interface of a second similar device via a ribbon cable. At this time, the control signal sent to the control input interface of either device will be synchronously transmitted to the isolated analog switching units of the two devices through this parallel line, thereby synchronously controlling the isolated analog switching units of all connected devices, and thus synchronously controlling the on / off state of the electrode channels at the same horizontal level in all devices.
[0038] Vertical Expansion: When vertical layer expansion is required, multiple devices of this invention can be stacked in series. The connection method is as follows: the "two-dimensional electrode input interface" of the upper-layer device and the "two-dimensional electrode expansion interface" of the lower-layer device are connected one-to-one via coaxial cables. Its operating logic is as follows: when measuring a specific target electrode layer, only the isolated analog switch unit of that layer's device is turned on according to the control signal, connecting its two-dimensional electrode input interface to its own three-dimensional shared electrode array; while the isolated analog switch units of all other layers remain off, thereby isolating their own electrode arrays from the signal path.
[0039] In summary, the core principle of vertical expansion lies in controlling the "on" and "off" of the analog switches inside different layers of the device to ensure that only the electrode array of the target measurement layer is connected at any given time, thereby realizing the function of controlling a multi-layer three-dimensional electrode array with a single two-dimensional device.
[0040] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.
Claims
1. A scalable three-dimensional electrical impedance imaging electrode array device, characterized in that, include: A two-dimensional electrode interface module is used to connect to the electrode output terminal of the original two-dimensional impedance measurement equipment. It includes multiple sets of two-dimensional electrode interface units. Each set of two-dimensional electrode interface units includes a two-dimensional electrode input interface for connecting to the electrode output of the original equipment and a two-dimensional electrode expansion interface for connecting to a lower-level similar device. The two-dimensional electrode input interface and the two-dimensional electrode expansion interface are connected in series. A three-dimensional shared electrode array for contacting the object under test includes multiple rows of measuring electrodes, each row containing multiple independent electrodes from different horizontal electrode array layers. A three-dimensional electrode control module, the input of which is connected to the output of the two-dimensional electrode interface module, and the output of which is connected to the three-dimensional common electrode array, the three-dimensional electrode control module comprising: The parallel electrode array control connector includes a control input interface and a control expansion interface, wherein the control input interface and the control expansion interface are connected in parallel and their corresponding control ports are electrically connected. An isolated analog switch unit includes multiple series-connected analog switches configured to electrically isolate the horizontal electrode channels and the vertical electrode layers from each other. The signal input terminal of the isolated analog switch unit is connected to the two-dimensional electrode input interface, its signal output terminal is connected to the three-dimensional common electrode array, and its control terminal is connected to the control input interface.
2. The apparatus according to claim 1, characterized in that, The isolated analog switch unit includes multiple sets of analog switch groups. Each set of analog switch groups consists of multiple series-connected analog switch units, which are used to control the switching on and off of multiple electrode signal channels from different horizontal planes in the vertical direction. Among them, the control terminals of all analog switch groups responsible for the signal channels at the same horizontal level are interconnected and lead to an independent control port of the control input interface; The isolated analog switch unit is configured to: respond to a control signal sent through a control port of the control input interface, uniformly control the on / off state of all electrode channels in the three-dimensional shared electrode array corresponding to a certain horizontal level.
3. The apparatus according to claim 2, characterized in that, The multiple sets of analog switches in the isolated analog switch unit are isolated from each other to achieve isolation between different signal channels in the horizontal direction; Furthermore, the multi-stage series analog switch units in each group of analog switches, through their cascaded turn-off capacitors, collectively increase the impedance of the channel in the off state, thereby achieving vertical isolation of non-gated horizontal plane signals.
4. The apparatus according to claim 2 or 3, characterized in that, Each column of measuring electrodes in the three-dimensional common electrode array has multiple independent electrodes that are respectively connected to different signal channels of the analog switch unit in the same group of analog switches that is directly electrically connected to the three-dimensional common electrode array.
5. The apparatus according to claim 1, characterized in that, The parallel structure of the control input interface and the control expansion interface is configured such that when the control expansion interface of this device is connected to the control input interface of another similar device, the control signal input to the control input interface of any device can synchronously control the isolated analog switch units of all connected devices, thereby synchronously controlling the on / off state of the electrode channels on the same horizontal level in all devices, and realizing the expansion of the number of electrodes in the horizontal direction.
6. The apparatus according to claim 1, characterized in that, The series structure of the two-dimensional electrode input interface and the two-dimensional electrode expansion interface is configured such that when the two-dimensional electrode expansion interface of this device is connected to the two-dimensional electrode input interface of another similar device, if the isolated analog switch unit of this device is in the conducting state, the electrode output signal of the original device is transmitted through the two-dimensional electrode input interface, the isolated analog switch unit and the three-dimensional common electrode array of this device. If the isolated analog switch unit of this device is in the off state, the electrode output signal of the original device is transmitted to the two-dimensional electrode input interface of the lower-level device through the two-dimensional electrode expansion interface, thereby realizing the expansion of the number of electrode array layers in the vertical direction.