Impedance calibrated diagnostic medical device

Abstract

Various embodiments set forth medical devices. In some embodiments, a medical device includes an impedance bridge, an instrument head including one or more electrode pairs and a calibration impedance, and one or more wire pairs coupling the impedance bridge to the one or more electrode pairs and the calibration impedance. The disclosed medical devices compensate for extraneous factors caused by manufacturing and material variations while measuring tissue impedance.

Description

[0001] Cross-references to related applications

[0002] This application claims the benefits of U.S. Provisional Patent Application No. 63 / 142,242, filed January 27, 2021; U.S. Provisional Patent Application No. 63 / 142,247, filed January 27, 2021; U.S. Provisional Patent Application No. 63 / 142,254, filed January 27, 2021; U.S. Provisional Patent Application No. 63 / 142,260, filed January 27, 2021; and U.S. Patent Application No. 17 / 397,896, filed August 9, 2021. Subject matter of these related applications is incorporated herein by reference. Technical Field

[0003] The embodiments of this disclosure generally relate to electronic and medical diagnostic technologies, and more specifically to impedance-calibrated diagnostic medical devices. Background Technology

[0004] During minimally invasive medical procedures, a healthcare provider inserts a medical device into an individual's body and positions the device's head at a target location (e.g., a tumor). Device heads include, but are not limited to: therapeutic drug delivery tools that deliver therapeutic drugs to the target location; energy delivery tools that deliver energy (e.g., heat or electricity) to the target location; and / or tissue sample extraction tools that extract tissue samples from the target location for further evaluation.

[0005] Delivering therapeutic drugs or energy to tissue outside the target site may result in the inability to treat the target site or damage to healthy tissue. Therefore, some instrument heads include electrode pairs that measure the impedance of the tissue at the instrument head location. Medical devices include, but are not limited to, leads that couple the electrode pairs in the instrument head to external electrical components, including, but not limited to, impedance bridges. A processor measures the impedance of the tissue in contact with the electrode pairs. A healthcare provider uses the measured impedance to determine the characteristics of the tissue in contact with the electrode pairs.

[0006] One drawback of the aforementioned medical devices is that various external factors frequently alter impedance measurement results. These external factors include, for example, variations in the materials and processes used to manufacture the medical devices (such as impedance bridges and leads). External factors can also include the length and arrangement of the leads coupling the electrode pairs to the impedance bridge, electromagnetic interference near the leads, and mechanical factors such as the length and bending of the leads. These types of external factors can cause incorrect tissue type at the location of the instrument head indicated by the electrical components of conventional medical devices.

[0007] As explained above, what is needed in the art is a more efficient technique for measuring tissue impedance. Summary of the Invention

[0008] Embodiments of impedance-calibrated diagnostic medical devices are disclosed. In various embodiments, a medical device includes: an impedance bridge; an instrument head including one or more electrode pairs and a calibration impedance; and one or more lead pairs coupling the impedance bridge to the one or more electrode pairs and the calibration impedance.

[0009] Embodiments for determining tissue characteristics are disclosed. In various embodiments, a method includes: recording one or more calibration impedance measurements associated with calibration impedance included in an instrument head of a medical device at one or more frequencies; recording one or more impedance measurements associated with one or more electrode pairs included in the instrument head at one or more frequencies; determining one or more compensated impedance measurements based on the one or more calibration impedance measurements and the one or more impedance measurements; and determining tissue characteristics based on the one or more compensated impedance measurements.

[0010] Furthermore, the embodiments provide systems and non-transient computer-readable media configured to implement the above methods.

[0011] At least one technical advantage of the disclosed medical device over the prior art is that it compensates for impedance caused by external factors due to manufacturing and material variations while measuring tissue impedance. For example, the disclosed medical device can compensate for conductor length and bending, as well as associated electromagnetic interference, while measuring tissue impedance. Therefore, the disclosed medical device measures tissue impedance more accurately than conventional medical devices that typically do not implement similar impedance compensation techniques. Consequently, the disclosed medical device can determine tissue characteristics, such as Cole relaxation frequency, tissue type, or the invasiveness of tumor tissue, more accurately than conventional medical devices. These technical advantages provide one or more technological advancements superior to existing methods. Attached Figure Description

[0012] Figure 1 Medical device 100 according to various embodiments is illustrated;

[0013] Figure 2 According to various embodiments Figure 1 A more detailed illustration of the instrument head 108;

[0014] Figure 3 According to various embodiments, including calibration impedance 302 Figure 2 A more detailed illustration of the instrument head 108;

[0015] Figure 4 It includes twisted pair 404, 406 according to various embodiments. Figure 2 A more detailed illustration of the instrument head 108;

[0016] Figure 5 It is coupled to according to various embodiments Figure 2 A more detailed illustration of the external electrical components 106 of the instrument head 108;

[0017] Figure 6 According to various embodiments Figure 1 More detailed illustrations of medical equipment 100; and

[0018] Figure 7 This is a flowchart of method steps for determining the characteristics of an organization according to various embodiments. Detailed Implementation

[0019] In the following description, numerous specific details are set forth to provide a more thorough understanding of the various embodiments. However, within the scope of the conceptual embodiments, some embodiments are included, with one or more of these specific details omitted.

[0020] Figure 1 A medical device 100 according to various embodiments is illustrated. As shown, the medical device 100 includes, but is not limited to, an instrument head 108, a lead wire 104, and an external electrical component 106. The instrument head 108 is positioned at a target location 102 (e.g., the location of a tumor). Although not shown, the instrument head 108 includes, but is not limited to, electrode pairs and tools that deliver therapeutic drugs or energy to the target location 102 and / or extract tissue samples from the target location 102 for further evaluation. The external electrical component 106 generates current at various frequencies. The lead wire 104 conducts current between the external electrical component 106 and the instrument head 108. The external electrical component 106 includes a processor that measures the impedance of the electrode pairs in the instrument head 108 and the tissue in contact with the electrode pairs. As described in more detail below, the medical device 100 reports the results of compensated impedance measurements and / or the characteristics of the tissue in contact with the electrode pairs based on the compensated impedance measurements to a healthcare provider during minimally invasive medical procedures. The tissue characteristics may include, but are not limited to, the Cole relaxation frequency, which indicates the rate or frequency of charge redistribution within cells. The characteristics of the tissue can include, but are not limited to, determining the tissue type of the contact electrode pair based on the Cole relaxation frequency, such as tumor or non-tumor determination. The characteristics of the tissue can also include, but are not limited to, determining the invasiveness of the tumor tissue of the contact electrode pair based on the Cole relaxation frequency.

[0021] Figure 2 According to various embodiments Figure 1A more detailed illustration of the instrument head 108 is provided. As shown, the instrument head 108 includes, but is not limited to, electrode pairs 202, tool 204, catheter 206, and lead 104. Electrode pairs 202 conduct current through tissue contacting electrode pairs 202 at various frequencies. Lead 104 conducts current between external electrical components 106 and electrode pairs 202 via catheter 206. In various embodiments, tool 204 delivers therapeutic drugs or energy (e.g., carried by a cannula or wire in catheter 206) and / or extracts tissue samples from target site 102 for further evaluation. The elements of the instrument head 108 allow a healthcare provider to measure the impedance of tissue contacting electrode pairs 202 in order to deliver therapeutic drugs or energy to target site 102 and / or extract tissue samples from target site 102 for further evaluation.

[0022] Figure 3 According to various embodiments, including calibration impedance 302 Figure 2 A more detailed illustration of the instrument head 108 is provided. As shown, the instrument head 108 includes, but is not limited to, a first electrode pair 202-1, a second electrode pair 202-2, a tool 204, and a calibration impedance 302. As shown, the instrument head 108 includes two electrode pairs 202-1 and 202-2; however, as used herein, the term "electrode pair 202" should be understood to include various embodiments having any number of electrode pairs 202, including but not limited to one electrode pair 202 or three or more electrode pairs 202. In various embodiments, the tool 204 includes, but is not limited to, a tool 204 for delivering therapeutic drugs or energy (e.g., heat or electricity) to the target site 102 and / or a tool 204 for extracting tissue samples from the target site 102 for further evaluation.

[0023] In various embodiments, the calibration impedance 302 is an impedance load of fixed and / or known impedance (i.e., resistance and / or reactance) included in the instrument head 108 during manufacturing. In various embodiments, the calibration impedance 302 includes, but is not limited to, two or more calibration impedance loads. For example, the calibration impedance load may include, but is not limited to: a phase offset calibration impedance load (e.g., a 100-ohm resistor) for determining the phase offset of the calibration impedance 302; a coarse gain calibration impedance load (e.g., a 510-ohm resistor) for determining the coarse gain of the calibration impedance 302; a fine gain calibration impedance load (e.g., a 300-ohm resistor) for determining the fine gain of the calibration impedance 302; and / or a phase calibration impedance load (e.g., a 0-ohm resistor) for determining the phase of the calibration impedance 302.

[0024] Figure 4 It includes twisted pair 404, 406 according to various embodiments. Figure 2A more detailed illustration of the instrument head 108 is provided. As shown, the instrument head 108 includes, but is not limited to, a first electrode pair 202-1, a second electrode pair 202-2, a tool 204, a catheter 206, a calibration impedance 302, a calibration impedance twisted pair 404, and an electrode twisted pair 406. The calibration impedance twisted pair 404 conducts current between the calibration impedance 302 and the external electrical component 106. The calibration impedance twisted pair 404 includes, but is not limited to, power and ground wires. The twisting of the calibration impedance twisted pair 404 reduces impedance caused by electromagnetic interference along the length of the calibration impedance twisted pair 404. The electrode twisted pair 406 conducts current between electrode pairs 202-1 and 202-2 and the external electrical component 106. The electrode twisted pair 406 includes, but is not limited to, power and ground wires. The twisting of the electrode twisted pair 406 reduces impedance caused by electromagnetic interference along the length of the electrode twisted pair 406. In various embodiments, two or more of the electrode pairs 202-1, 202-2 share a power line and / or ground line in the electrode twisted pair 406. In some other embodiments, each of the two or more electrode pairs 202-1, 202-2 has a power line and / or ground line in the electrode twisted pair 406. For example, but not limited to, the instrument head 108 may include two electrode pairs 202, wherein each electrode pair 202 includes an electrode twisted pair 406 that couples the electrode pair to an external electrical component 106. Thus, each of the two electrode pairs 202 can be driven by a separate current source and reference a separate return lead, and the external electrical component 106 can record four-lead impedance measurements.

[0025] Although not shown, in various embodiments, the instrument head 108 includes, but is not limited to, a buffer circuit positioned near the electrode pair 202. The buffer circuit isolates the output of the electrode pair 202 from parasitic capacitance caused by external electrical components 106 coupled to the output of the electrode pair 202 via electrode twisted pair 406. Alternatively, in some embodiments, the output of the buffer circuit and the input of impedance bridge 504 are coupled via an analog-to-digital converter (ADC) circuit that converts the analog output of the buffer circuit into a digital signal. The digital signal can be transmitted to the external electrical components 106 via a medium such as, but not limited to, cables or wires (e.g., optical fibers) and / or radio electromagnetic signals (e.g., Bluetooth). Converting the signal to a digital output further reduces external influences on signal quality, such as parasitic capacitance or ambient electromagnetic interference.

[0026] Figure 5 It is coupled to according to various embodiments Figure 2A more detailed illustration of the external electrical components 106 of the instrument head 108 is provided. As shown, the external electrical components 106 include a calibration impedance twisted pair 404, an electrode twisted pair 406, an amplifier 502, an impedance bridge 504, and a processor 506. The calibration impedance twisted pair 404 conducts currents of various frequencies between the calibration impedance 302 and the external electrical components 106. The electrode twisted pair 406 conducts currents of various frequencies between the electrode pair and the external electrical components 106. In various embodiments, the amplifier 502 is an analog interface amplifier that amplifies the supplied voltage and / or the return voltage, while the calibration impedance twisted pair 404 conducts currents of various frequencies between the impedance bridge 504 and the calibration impedance 302, and / or the electrode twisted pair 406 conducts currents of various frequencies between the impedance bridge 504 and the electrode pair 202. In various embodiments, the impedance bridge 504 is an impedance load that the processor 506 measures to determine the impedance of the circuitry including the impedance bridge 504, amplifier 502, calibration impedance twisted pair 404, and instrument head 108 (e.g., electrode pair 202 and / or calibration impedance 302).

[0027] In various embodiments, processor 506 measures the impedance of impedance bridge 504 to determine the impedance of circuitry including impedance bridge 504, amplifier 502, calibration impedance twisted pair 404, and instrument head 108. Processor 506 generates the frequency of the current conducted by calibration impedance twisted pair 404 between impedance bridge 504 and calibration impedance 302, and measures the impedance of impedance bridge 504. As calibration impedance twisted pair 404 conducts this current at various frequencies, processor 506 records one or more calibration impedance measurements 508 of the circuitry including calibration impedance 302. In various embodiments, the calibration impedance measurements at various frequencies include, but are not limited to, phase offset measurements, coarse gain measurements, fine gain measurements, and / or phase measurements. In various embodiments, processor 506 records the various measurements of calibration impedance measurements 508 while the circuitry includes one or more calibration impedance loads for calibration impedance 302. In various embodiments, the calibration impedance loads include, but are not limited to, phase calibration impedance loads; coarse gain calibration impedance loads; fine gain calibration impedance loads; and / or phase calibration impedance loads. In various embodiments, processor 506 measures and records one or more calibration impedance measurements 508 (e.g., phase offset measurements, coarse gain, and phase) during a factory calibration process. In various embodiments, processor 506 measures and records one or more calibration impedance measurements 508 (e.g., fine gain) during a surgical calibration process.

[0028] Processor 506 generates the frequency of the current conducted by electrode twisted pair 406 between impedance bridge 504 and electrode pair 202, and measures the impedance of impedance bridge 504. As the electrode impedance twisted pair 406 conducts this current at various frequencies, processor 506 records one or more impedance measurements 510 of the circuit including electrode pair 202. In various embodiments, the frequency of the current used to calibrate impedance measurement 508 is the same as, similar to, or different from the frequency used to measure impedance measurement 510. For example, processor 506 may measure the calibration impedance measurement 508 at each frequency in a first set of frequencies, and may measure the impedance measurement 510 at each frequency in a second set of frequencies different from the first set of frequencies.

[0029] In various embodiments, processor 506 determines one or more compensated impedance measurements 512 based on calibration impedance measurement result 508 and impedance measurement result 510. For example, processor 506 subtracts or divides the calibration impedance measurement result 508 from impedance measurement result 510. The compensated impedance measurement result 512 indicates the impedance of the contact electrode to the tissue of 202.

[0030] In various embodiments, processor 506 determines a characteristic 514 of the tissue to which the contact electrode is attached to 202 based on a compensated impedance measurement result 512. In various embodiments, characteristic 514 includes, but is not limited to: the Cole relaxation frequency of the tissue; the tissue type (e.g., the tissue is identified as tumor or non-tumor); and / or the invasiveness of tumor tissue. For example, the Cole relaxation frequency is the frequency of the maximum normalized impedance measurement result of the contact electrode to the tissue of 202. The Cole relaxation frequency is determined to be below a threshold frequency (e.g., 10). 5 The probability that the tissue at contact electrode 202 is normal tissue is increased (Hz). Determining that the Cole relaxation frequency is above a threshold frequency indicates an increased probability that the tissue at contact electrode 202 is tumorous. By determining the compensated impedance measurement result 512, processor 506 determines characteristic 514 based on the tissue's impedance (excluding impedance due to external factors). In various embodiments, processor 506 reports characteristic 514 to the user of medical device 100. In various embodiments, processor 506 controls tool 204 of instrument head 108 based on characteristic 514. For example, processor 506 causes tool 204 to deliver therapeutic drugs or energy to target location 102 based on the compensated impedance measurement result 512 indicating that the tissue at contact electrode 202 is tumorous.

[0031] Figure 6 According to various embodiments Figure 1A more detailed illustration of the medical device 100 is provided. As shown, the medical device 100 includes an instrument head 108 and external electrical components 106 coupled via a calibration impedance twisted pair 404 and an electrode twisted pair 406. As shown, the instrument head 108 includes a calibration impedance 302 and electrode pairs 202. The calibration impedance 302 includes, but is not limited to, one or more impedance loads with known and / or fixed impedances (e.g., resistance and / or reactance). In various embodiments, the instrument head 108 includes, but is not limited to, two or more electrode pairs 202 sharing the electrode twisted pair 406, and / or two or more electrode pairs 202 individually coupled to the electrode twisted pair 406. Although not shown, in various embodiments, the instrument head 108 includes, but is not limited to, a tool 204 for delivering therapeutic drugs or energy (e.g., heat or electricity) to a target location 102.

[0032] As shown in the figure, the external electrical component 106 includes an amplifier 502, an impedance bridge 504, and a processor 506. The amplifier 502 amplifies the supplied voltage and / or return voltage, while the calibration impedance twisted pair 404 and / or the electrode twisted pair 406 conduct currents of various frequencies between the impedance bridge 504 and the instrument head 108. The impedance bridge 504 is an impedance load, which the processor 506 measures to determine the impedance of a circuit comprising one or more components including the impedance bridge 504, the amplifier 502, the calibration impedance twisted pair 404 or the electrode twisted pair 406, and the instrument head 108. The processor 506 records one or more calibration impedance measurements 508 at various frequencies. The processor 506 records one or more impedance measurements 510 at various frequencies. Based on the calibration impedance measurements 508 and the impedance measurements 510, the processor 506 determines one or more compensated impedance measurements 512. Based on the compensated impedance measurements 512, the processor 506 determines the tissue characteristics 514 of the contact electrode pair 202. In various embodiments, characteristic 514 includes, but is not limited to: the Cole relaxation frequency of the tissue; the tissue type of the tissue (e.g., the tissue is identified as tumor or non-tumor); and / or the invasiveness of tumor tissue. By determining the compensated impedance measurement result 512, the medical device 100 determines characteristic 514 based on the impedance of the tissue (excluding impedance due to external factors). In various embodiments, based on characteristic 514, the medical device 100 reports characteristic 514 to the user and / or control tool 204 of the medical device 100 (e.g., to deliver therapeutic drugs or energy to a target location and / or to extract tissue samples from the target location for further evaluation). For example, the medical device 100 uses visual output (e.g., a liquid crystal display (LCD), a light-emitting diode (LED) display, or an indicator, etc.) to display indications of the characteristic and / or uses audio output (e.g., using a speaker, buzzer, etc. to present audio cues of the device characteristic, such as verbal descriptions, sound effects, etc.) to present audio indications of the characteristic.

[0033] Figure 7 This is a flowchart of method steps for determining the characteristics 514 of an organization according to various embodiments. Although combined... Figures 1 to 6 The system describes the method steps, but those skilled in the art will understand that any system configured to perform the method steps in any order falls within the scope of this invention.

[0034] As shown in the figure, method 700 begins at step 702, wherein a processor 506 of medical device 100 records one or more calibration impedance measurements 508 of calibration impedance 302 within the instrument head 108 of medical device 100 at one or more frequencies. In various embodiments, processor 506 may record the calibration impedance measurements 508 in the memory of medical device 100 or in the memory of another device such as a server. For example, processor 506 may record the calibration impedance measurements 508 as part of a manufacturing process (e.g., performed by a supplier) and / or as part of a medical procedure. The calibration impedance measurements 508 indicate impedance due to external factors, including (but not limited to) variations in materials, electromagnetic interference, or the length or bending of the conductor 104.

[0035] In step 704, processor 506 records one or more impedance measurements 510 of one or more electrode pairs 202 within instrument head 108 at one or more frequencies. In various embodiments, processor 506 records the impedance measurements 510 at the same or similar frequencies as the calibration impedance measurements 508, or at different frequencies (e.g., a more limited set of frequencies). The impedance measurements 510 indicate the impedance of the tissue in contact with one or more electrode pairs 202 and the impedance due to external factors, as previously described.

[0036] In step 706, processor 506 determines one or more compensated impedance measurements 512 based on the calibration impedance measurement result 508 and the impedance measurement result 510. In various embodiments, processor 506 determines the compensated impedance measurement result 512 by subtracting the calibration impedance measurement result 508 from the impedance measurement result 510 and / or by dividing the impedance measurement result 510 by the calibration impedance measurement result 508. The compensated impedance measurement result 512 indicates the impedance of the tissue in contact with one or more electrodes 202, excluding impedance due to external factors.

[0037] In step 708, processor 506 determines a tissue characteristic 514 based on one or more compensated impedance measurements 512. In various embodiments, characteristic 514 includes, but is not limited to: the tissue's Coel relaxation frequency; the tissue type (e.g., the tissue is identified as tumor or non-tumor); and / or the invasiveness of tumor tissue. Performing the determination based on compensated impedance measurements 512 enables medical device 100 to determine characteristic 514 based on the tissue's impedance, excluding impedance due to external factors. In various embodiments, medical device 100 may use the determined characteristic, for example, but not limited to, by reporting characteristic 514 to a user of medical device 100 and / or by controlling tool 204 based on characteristic 514. After step 708, processor 506 returns to step 704 to record additional impedance measurements 510.

[0038] In summary, the disclosed medical device measuring instrument head uses a calibration impedance to determine the impedance caused by external factors. When the medical device subsequently measures the impedance of the tissue contacting the electrode pair, it compensates for the tissue impedance measurement based on the calibration impedance measurement. This compensation technique advantageously reduces the impedance-changing effect of external factors on the tissue impedance measurement results.

[0039] At least one technical advantage of the disclosed medical device over the prior art is that it compensates for impedance caused by external factors due to manufacturing and material variations while measuring tissue impedance. For example, the disclosed medical device can compensate for the length and bending of the conductor and associated electromagnetic interference while measuring tissue impedance. Therefore, the disclosed medical device measures tissue impedance more accurately than conventional medical devices that typically do not implement similar impedance compensation techniques. Consequently, the disclosed medical device can determine tissue characteristics, such as Cole relaxation frequency, tissue type, or the invasiveness of tumor tissue, more accurately than conventional medical devices. These technical advantages provide one or more technological advancements superior to existing methods.

[0040] 1. In some embodiments, a medical device includes: an impedance bridge; an instrument head including one or more electrode pairs and a calibration impedance; and one or more lead pairs that couple the impedance bridge to the one or more electrode pairs and the calibration impedance.

[0041] 2. The medical device according to Clause 1, wherein one or more lead pairs include at least one of a calibration impedance twisted pair that couples a calibration impedance to an impedance bridge or an electrode impedance twisted pair that couples one or more electrode pairs to an impedance bridge.

[0042] 3. A medical device according to Clause 1 or 2, wherein one or more electrode pairs comprise two electrode pairs, one or more lead pairs comprise two lead pairs, and each lead pair bridges an impedance to different electrode pairs in the two electrode pairs.

[0043] 4. A medical device according to any one of clauses 1 to 3, wherein the instrument head further includes at least one of a therapeutic drug delivery tool, an energy delivery tool, or a tissue sample extraction tool.

[0044] 5. A medical device according to any one of clauses 1 to 4, wherein the calibration impedance includes at least one of phase offset calibration impedance load, coarse gain calibration impedance load, fine gain calibration impedance load or phase calibration impedance load.

[0045] 6. A medical device according to any one of clauses 1 to 5, wherein the instrument head further includes a buffer circuit that couples the output of one or more electrode pairs to an impedance bridge.

[0046] 7. A medical device according to any one of clauses 1 to 6, wherein the output of the buffer circuit and the input of the impedance bridge are coupled by an analog-to-digital converter that converts the output of the buffer circuit into a digital output.

[0047] 8. A medical device according to any one of clauses 1 to 7 further includes a current generator that causes one or more pairs of leads to conduct current between the instrument head and the impedance bridge at one or more frequencies.

[0048] 9. A medical device according to any one of clauses 1 to 8 further includes a processor that measures at least one of the following: a calibration impedance measurement associated with a current flowing between an impedance bridge and a calibration impedance at one or more frequencies, or an impedance measurement associated with a current flowing between an impedance bridge and one or more electrode pairs at one or more frequencies.

[0049] 10. A medical device according to any one of clauses 1 to 9 further includes a processor that determines at least one of the following: characteristics of a tissue portion in contact with one or more electrode pairs, based on one or more calibrated impedance measurements and one or more compensated impedance measurements.

[0050] 11. In some embodiments, a method for determining tissue characteristics includes: recording one or more calibration impedance measurements associated with calibration impedance included in an instrument head of a medical device at one or more frequencies; recording one or more impedance measurements associated with one or more electrode pairs included in the instrument head at one or more frequencies; determining one or more compensated impedance measurements based on the one or more calibration impedance measurements and the one or more impedance measurements; and determining tissue characteristics based on the one or more compensated impedance measurements.

[0051] 12. The method according to Clause 11, wherein recording one or more calibration impedance measurement results includes recording at least one of the following: phase shift of calibration impedance measurement results based on calibration impedance load, coarse gain of calibration impedance measurement results based on coarse gain calibration impedance load, fine gain of calibration impedance measurement results based on fine gain calibration impedance load, or phase of calibration impedance measurement results based on phase calibration impedance load.

[0052] 13. The method according to any one of Clauses 11 to 12, wherein recording one or more calibration impedance measurements includes recording one or more of one or more calibration impedance measurements during a factory calibration process or recording one or both of one or more calibration impedance measurements during a surgical calibration process.

[0053] 14. The method according to any one of clauses 11 to 13, wherein recording one or more calibration impedance measurements comprises: measuring one or more calibration impedance measurements at various frequencies included in a first set of frequencies, and recording one or more impedance measurements comprises: measuring one or more impedance measurements associated with one or more electrode pairs at various frequencies included in a second set of frequencies, wherein the second set of frequencies is different from the first set of frequencies.

[0054] 15. The method according to any one of clauses 11 to 14, wherein recording one or more impedance measurement results includes recording a first impedance measurement result based on a first current associated with a first electrode pair and a first conductor pair, and recording a second impedance measurement result based on a second current associated with a second electrode pair and a second conductor pair.

[0055] 16. The method according to any one of Clauses 11 to 15, wherein determining one or more compensated impedance measurements includes one or both of the following operations: subtracting one or more calibrated impedance measurements from one or more impedance measurements, or dividing one or more impedance measurements by one or more calibrated impedance measurements.

[0056] 17. The method according to any one of clauses 11 to 16, wherein determining the characteristics of the organization includes determining the Cole relaxation frequency of the organization based on one or more compensated impedance measurements.

[0057] 18. The method according to any one of clauses 11 to 17, wherein the Cole relaxation frequency corresponds to the frequency associated with the maximum compensated impedance measurement included in one or more compensated impedance measurements.

[0058] 19. The method according to any one of clauses 11 to 18, wherein determining the characteristics of an organization further includes determining the organization type based on the organization's Cole relaxation frequency.

[0059] 20. The method according to any one of clauses 11 to 19, wherein determining the characteristics of the tissue includes determining the invasiveness of the tumor tissue based on Cole relaxation frequencies.

[0060] 21. The method according to any one of clauses 11 to 20, wherein determining the characteristics of the tissue includes determining the tumor tissue type of the tissue based on the Cole relaxation frequency of the tissue being higher than a threshold frequency, and determining the non-tumor tissue type of the tissue based on the Cole relaxation frequency of the tissue being lower than a threshold frequency.

[0061] 22. The method according to any one of clauses 11 to 21 further includes using at least one of visual output or audio output to present the characteristics of the tissue of the medical device.

[0062] 23. The method according to any one of clauses 11 to 22 further includes a tool for controlling the instrument head based on tissue characteristics, the tool including at least one of a therapeutic drug delivery tool, an energy delivery tool, or a tissue sample extraction tool.

[0063] Any element of any claim recited in any claim and / or any combination of any element described in this application falls within the scope of the invention and protection in any way.

[0064] Various embodiments have been described for illustrative purposes, but are not intended to be exhaustive or limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

[0065] Aspects of the embodiments of this application can be embodied as systems, methods, or computer program products. Therefore, aspects of this disclosure can take the form of entirely hardware embodiments, entirely software embodiments (including firmware, resident software, microcode, etc.), or embodiments combining software and hardware aspects, all of which can be generally referred to herein as “modules,” “systems,” or “computers.” Furthermore, any hardware and / or software techniques, processes, functions, components, engines, modules, or systems described in this disclosure can be implemented as circuits or groups of circuits. Additionally, aspects of this disclosure can take the form of computer program products embodied in one or more computer-readable media, on which computer-readable program code is embodied.

[0066] Any combination of one or more computer-readable media may be used. A computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. A computer-readable storage medium can be, for example, but not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatuses, or devices, or any suitable combination thereof. More specific examples (not an exhaustive list) of computer-readable storage media will include: electrical connections having one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable optical disc read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing media. In the context of this document, a computer-readable storage medium can be any tangible medium that can contain or store a program used by or in conjunction with an instruction execution system, apparatus, or device.

[0067] The aspects of this disclosure have been described above with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this disclosure. It should be understood that individual blocks of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus to produce a machine. When executed via the processor of a computer or other programmable data processing apparatus, the instructions enable the implementation of the functions / actions specified in one or more blocks of the flowchart illustrations and / or block diagrams. Such a processor can be, but is not limited to, a general-purpose processor, a special-purpose processor, an application-specific processor, or a field-programmable gate array (FPGA).

[0068] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present disclosure. In this regard, the individual blocks in the flowcharts or block diagrams may represent modules, segments, or portions of code, including one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions labeled in the blocks may occur in a different order than indicated in the figures. For example, two blocks shown consecutively may actually be executed substantially simultaneously, or the blocks may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that the individual blocks in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, may be implemented by a system based on dedicated hardware or a combination of dedicated hardware and computer instructions that performs the specified function or action.

[0069] While the foregoing relates to embodiments of this disclosure, other and additional embodiments of this disclosure may be devised without departing from the basic scope of this disclosure, the scope of which is defined by the appended claims.

Claims

1. A medical device comprising: Impedance bridge; Instrument head, including: One or more electrode pairs; and Calibration impedance; and Multiple conductor pairs, including: a calibration impedance conductor pair coupling the calibration impedance to the impedance bridge, and an electrode impedance conductor pair coupling the one or more electrode pairs to the impedance bridge.

2. The medical device of claim 1, wherein, The calibration impedance wire pair and the electrode impedance wire pair are twisted pairs.

3. The medical device of claim 1, wherein, The one or more electrode pairs include two electrode pairs, the plurality of wire pairs include two wire pairs, and each wire pair couples the impedance bridge to different electrode pairs in the two electrode pairs.

4. The medical device of claim 1, wherein, The instrument head also includes at least one of a therapeutic drug delivery tool, an energy delivery tool, or a tissue sample extraction tool.

5. The medical device of claim 1, wherein, The calibration impedance includes at least one of phase offset calibration impedance load, coarse gain calibration impedance load, fine gain calibration impedance load, or phase calibration impedance load.

6. The medical device of claim 1, wherein, The instrument head also includes a buffer circuit that couples the output of the one or more electrode pairs to the impedance bridge.

7. The medical device of claim 6, wherein, The output of the buffer circuit and the input of the impedance bridge are coupled by an analog-to-digital converter that converts the output of the buffer circuit into a digital output.

8. The medical device of claim 1 further includes a current generator that causes the plurality of wire pairs to conduct current between the instrument head and the impedance bridge at one or more frequencies.

9. The medical device of claim 1, further comprising a processor that measures at least one of the following: a calibration impedance measurement associated with a current flowing between the impedance bridge and the calibration impedance at one or more frequencies, or an impedance measurement associated with a current flowing between the impedance bridge and the one or more electrode pairs at one or more frequencies.

10. The medical device of claim 1, further comprising a processor that determines at least one of the following: a compensated impedance measurement based on one or more calibrated impedance measurements and one or more impedance measurements, or the characteristics of the tissue portion in contact with the one or more electrode pairs.

11. A computer-implemented method for determining the characteristics of an organization, the method comprising: Record one or more calibration impedance measurements associated with a calibration impedance included in an instrument head of a medical device at one or more frequencies. The medical device also includes an impedance bridge and a plurality of lead pairs, including calibration impedance lead pairs and electrode impedance lead pairs, wherein the calibration impedance is coupled to the impedance bridge via the calibration impedance lead pairs. Record one or more impedance measurements associated with one or more electrode pairs included in the instrument head at one or more frequencies, the one or more electrode pairs being coupled to the impedance bridge via the electrode impedance wire pair; One or more compensation impedance measurements are determined based on the one or more calibration impedance measurements and the one or more impedance measurements. as well as The characteristics of the tissue are determined based on the results of one or more compensated impedance measurements.

12. The method of claim 11, wherein, Recording the one or more calibration impedance measurement results includes recording at least one of the following: phase shift of the calibration impedance measurement result based on the calibration impedance load, coarse gain of the calibration impedance measurement result based on the coarse gain calibration impedance load, fine gain of the calibration impedance measurement result based on the fine gain calibration impedance load, or phase of the calibration impedance measurement result based on the phase calibration impedance load.

13. The method of claim 11, wherein, Recording the results of one or more calibration impedance measurements includes one or both of the following operations: Record one or more of the calibration impedance measurements during the factory calibration process; or Record one or more of the calibration impedance measurements during the surgical calibration process.

14. The method according to claim 11, wherein, Recording the one or more calibration impedance measurement results includes: measuring the one or more calibration impedances at each frequency included in the first set of frequencies, and Recording the one or more impedance measurement results includes measuring the one or more impedance measurement results associated with the one or more electrode pairs at various frequencies included in the second set of frequencies, wherein the second set of frequencies is different from the first set of frequencies.

15. The method of claim 11, wherein, Recording the one or more impedance measurement results includes: recording a first impedance measurement result based on a first current associated with a first electrode pair and a first conductor pair, and recording a second impedance measurement result based on a second current associated with a second electrode pair and a second conductor pair.

16. The method of claim 11, wherein, Determining the results of the one or more compensated impedance measurements includes one or both of the following operations: Subtract the one or more calibrated impedance measurements from the one or more impedance measurements; or Divide the one or more impedance measurement results by the one or more calibrated impedance measurement results.

17. The method of claim 11, wherein, Determining the characteristics of the tissue includes determining the Cole relaxation frequency of the tissue based on the results of one or more compensated impedance measurements.

18. The method of claim 17, wherein, The Cole relaxation frequency corresponds to the frequency associated with the maximum compensation impedance measurement included in the one or more compensation impedance measurements.

19. The method of claim 18, wherein, Determining the characteristics of the organization also includes determining the organization type based on the organization's Cole relaxation frequency.

20. The method of claim 18, wherein, Determining the characteristics of the tissue includes determining the invasiveness of the tumor tissue based on the Cole relaxation frequency.

21. The method of claim 11, wherein, Determining the characteristics of the organization includes: The tumor tissue type of the tissue is determined based on the Cole relaxation frequency of the tissue being higher than a threshold frequency; and The non-tumor tissue type of the tissue is determined based on the Cole relaxation frequency of the tissue being lower than the threshold frequency.

22. The method of claim 11, further comprising using at least one of visual output or audio output to present the characteristics of the tissue of the medical device.

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