Implantable Electrical Stimulation Device and Its Control Method, Device and System

Abstract

The present invention provides an implantable electrical stimulation device, its control method, device and system. The device includes: a controller, an impedance detection device, a stimulation circuit, a switching circuit and a collection circuit. The controller is configured to: obtain the characteristic value of the waveform of the ECAP signal of the patient's body in the current posture; measure the first impedance value of the patient's body located between the first electrode contact and the second electrode contact through the impedance detection device, and determine the contact situation between the first electrode contact and the second electrode contact and the patient's body based on the first impedance value; determine whether to switch different electrode contacts to deliver pulses according to the contact situation and the characteristic value. So as to switch to a suitable electrode contact in time to output therapeutic pulses when the electrode contact is twisted and has poor contact with the patient's body, realize precise stimulation of the treatment site, and ensure the accuracy of the treatment process and the treatment effect.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and particularly to an implantable electrical stimulation device, its control method, device and system. Background Art

[0002] With the development of medical technology, implantable electrical stimulation has become a commonly used treatment method for treating pain symptoms. Implantable medical devices usually deliver stimulation pulses by contacting the electrode contacts on the electrode leads with the patient's nervous system or nerve system, so as to relieve the patient's pain and achieve the treatment purpose.

[0003] Considering that in practical applications, during the process of the patient's posture change, the position of the electrode contacts relative to the patient's nervous system may move, resulting in a change in the contact part between the electrode contacts and the patient's nervous system, and the problem of inaccurate stimulation occurs, affecting the treatment effect and experience of the patient.

[0004] Therefore, how to improve the accuracy of electrical stimulation of implantable electrical stimulation devices is a technical problem that those skilled in the art urgently need to solve. Summary of the Invention

[0005] In view of this, embodiments of the present invention are committed to providing an implantable electrical stimulation device, its control method, device and system, aiming to improve the accuracy of electrical stimulation.

[0006] In a first aspect, the present invention provides an implantable electrical stimulation device, including: a controller, an impedance detection device connected to the controller for detecting the impedance value between electrode contacts; a stimulation circuit configured to generate pulses and output the pulses through the electrode contacts on the electrode leads; a switch circuit connected between the controller and the electrode leads, configured to conduct the electrode contacts and the stimulation circuit under the control of the controller to switch different electrode contacts to output pulses; an acquisition circuit electrically connected to the controller, configured to receive the evoked compound action potential (ECAP) signal generated by the stimulation circuit stimulating the patient's body with pulses after the controller controls the stimulation circuit and the acquisition circuit to conduct with the electrode contacts. Wherein, the controller is configured to perform the following steps:

[0007] Obtain the characteristic value of the waveform of the ECAP signal of the patient's body based on the current posture; measure the first impedance value between the first electrode contact and the second electrode contact on the electrode lead of the implantable electrical stimulation device in real time through an impedance detection device, where the first impedance value is the actual impedance value of the patient's body between the first electrode contact and the second electrode contact, and the electrode contact groups where the first electrode contact and the second electrode contact are located are different and are used to output pulses; determine the contact situation between the first electrode contact and the second electrode contact and the body based on the first impedance value; determine whether to switch to different electrode contacts to output pulses according to the contact situation and the characteristic value; and in the case of determining to switch to different electrode contacts, switch to the third electrode contact and the fourth electrode contact through a switching circuit to deliver pulses to the body.

[0008] In an embodiment provided by the present invention, determining the contact situation between the first electrode contact and the second electrode contact and the body based on the first impedance value includes: comparing the first impedance value with a first threshold, where the first threshold is the threshold range of the impedance between the first electrode contact and the second electrode contact; when the first impedance value is greater than the first threshold, determine that at least one of the first electrode contact and the second electrode contact has poor contact with the body.

[0009] In an embodiment provided by the present invention, when the first impedance value is greater than the first threshold, determining that at least one of the first electrode contact and the second electrode contact has poor contact with the body includes: when the first impedance value is greater than the first threshold and less than the second threshold, determine that at least one of the first electrode contact and the second electrode contact partially contacts the body, or at least one of the first electrode contact and the second electrode contact partially contacts the body, and at the same time, one of the other electrode contacts in the corresponding electrode contact group partially contacts the body; when the first impedance value is greater than the second threshold, determine that at least one of the first electrode contact and the second electrode contact does not contact the body.

[0010] In an embodiment provided by the present invention, determining whether to switch to different electrode contacts to output pulses according to the contact situation and the characteristic value includes: when the first impedance value is greater than the second threshold, determine to switch to different electrode contacts to deliver pulses; when the first impedance value is greater than the first threshold and less than the second threshold, compare the characteristic value with a third threshold, and when the characteristic value is greater than the third threshold, determine to switch to different electrode contacts to deliver pulses.

[0011] In an embodiment provided by the present invention, switching to different electrode contacts to deliver pulses includes: determining the electrode contact of the new output pulse according to the impedance values of the other electrode contacts in the electrode contact group where the electrode contact of the current output pulse is located; switching the electrode contact of the current output treatment pulse to the electrode contact of the new output pulse.

[0012] In an embodiment provided by the present invention, the controller is further configured to: measure a second impedance value between a first electrode contact and a fifth electrode contact on an electrode lead of an implantable electrical stimulation device through an impedance detection device, where the second impedance value is the actual impedance value of the patient's body between the first electrode contact and the fifth electrode contact, and the first electrode contact and the fifth electrode contact are in different electrode contact groups for outputting pulses; compare the second impedance value with a first threshold, and when the second impedance value is not greater than the first threshold, determine that the second electrode contact has poor contact with the body.

[0013] In an embodiment provided by the present invention, the controller is further configured to: when the second impedance value is greater than the first threshold, measure a third impedance value between a second electrode contact and a fifth electrode contact on an electrode lead of the implantable electrical stimulation device through the impedance detection device, where the third impedance value is the actual impedance value of the patient's body between the second electrode contact and the fifth electrode contact, and the second electrode contact and the fifth electrode contact are in different electrode contact groups; compare the third impedance value with the first threshold; when the third impedance value is not greater than the first threshold, determine that the first electrode contact has poor contact with the body; when the third impedance value is greater than the first threshold, determine that both the first electrode contact and the second electrode contact have poor contact with the body.

[0014] In an embodiment provided by the present invention, obtaining the eigenvalue of the waveform of the ECAP signal when the patient's body is under the current stimulation parameter value includes: determining the waveform of the ECAP signal when the patient's body is in the current posture; extracting the eigenvalue of the waveform based on a deep learning algorithm.

[0015] In an embodiment provided by the present invention, the real-time measurement of the first impedance value between a first electrode contact and a second electrode contact on an electrode lead of the implantable electrical stimulation device includes: measuring the measured voltage value between the first electrode contact and the second electrode contact; measuring the measured current value between the first electrode contact and the second electrode contact; obtaining the impedance value between the first electrode contact and the second electrode contact based on the measured voltage value and the measured current value.

[0016] In a second aspect, the present invention provides a control method for the implantable electrical stimulation device described in the first aspect, including: obtaining characteristic values of the waveform of the ECAP signal of the patient's body in the current posture; measuring in real time a first impedance value between a first electrode contact and a second electrode contact on the electrode lead of the implantable electrical stimulation device, where the first impedance value is the actual impedance value of the patient's body located between the first electrode contact and the second electrode contact, and the first electrode contact and the second electrode contact are in different electrode contact groups for outputting pulses; determining the contact situation between the first electrode contact and the second electrode contact and the body based on the first impedance value; determining whether to switch to different electrode contacts to output pulses according to the contact situation and the characteristic values; and in the case of determining to switch to different electrode contacts, switching to a third electrode contact and a fourth electrode contact to deliver pulses to the body.

[0017] In a third aspect, the present invention provides a control device for the implantable electrical stimulation device described in the first aspect. The device includes: an acquisition module configured to obtain characteristic values of the waveform of the ECAP signal of the patient's body in the current posture; a measurement module configured to measure in real time a first impedance value between a first electrode contact and a second electrode contact on the electrode lead of the implantable electrical stimulation device, the first impedance value being the actual impedance value of the patient's body located between the first electrode contact and the second electrode contact, and the first electrode contact and the second electrode contact being in different electrode contact groups for outputting pulses; a determination module configured to determine the contact situation between the first electrode contact and the second electrode contact and the body based on the first impedance value, and determine whether it is necessary to switch to different electrode contacts to output pulses according to the contact situation and the characteristic values; an adjustment module configured to, in the case of determining to switch to different electrode contacts to output pulses, switch to a third electrode contact and a fourth electrode contact to deliver pulses to the body.

[0018] In a fourth aspect, the present invention provides an implantable electrical stimulation system, including: the implantable electrical stimulation device described in the first aspect; an electrode lead connected to the implantable electrical stimulation device for delivering pulses to the patient's body.

[0019] An embodiment of the present invention provides an implantable electrical stimulation device, its control method, device and system. The device includes: a controller, an impedance detection device, a stimulation circuit, a switching circuit and an acquisition circuit. The controller is configured to: obtain the characteristic value of the waveform of the ECAP signal of the patient's body in the current posture; measure the first impedance value of the patient's body between the first electrode contact and the second electrode contact through the impedance detection device, and determine the contact situation between the first electrode contact and the second electrode contact and the patient's body based on the first impedance value; determine whether to switch different electrode contacts to deliver pulses according to the contact situation and the characteristic value. When the electrode contact is twisted and the contact with the patient's body is poor, it can be timely switched to a suitable electrode contact to output a treatment pulse, so as to achieve precise stimulation of the treatment site and ensure the accuracy of the treatment process and the treatment effect. Description of the Drawings

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present disclosure. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0021] Figure 1 Schematic diagram of an implantable electrical stimulation system provided by an embodiment of the present invention.

[0022] Figure 2 Schematic diagram of the structure of an implantable electrical stimulation device provided by an embodiment of the present invention.

[0023] Figure 3 Schematic diagram of the structure of an electrode lead provided by an embodiment of the present invention.

[0024] Figure 4 Provided by an embodiment of the present invention Figure 3 Cross-sectional view taken along the longitudinal direction (direction A) of the electrode lead shown.

[0025] Figure 5 Flow chart of the control method of the implantable electrical stimulation device provided by an exemplary embodiment of the present invention.

[0026] Figure 6 Flow chart of the method for judging the contact situation between the electrode contact and the patient's body provided by an embodiment of the present invention.

[0027] Figure 7 Schematic diagram of the contact situation between an electrode contact and the patient's body provided by an embodiment of the present invention.

[0028] Figure 8Another structural schematic diagram of the contact situation between an electrode contact and a patient's body provided by an embodiment of the present invention.

[0029] Figure 9 Another structural schematic diagram of the contact situation between an electrode contact and a patient's body provided by an embodiment of the present invention.

[0030] Figure 10 A flowchart showing a method for determining an electrode contact with poor contact with a patient's body provided by an embodiment of the present invention.

[0031] Figure 11 A system module schematic diagram of a control device of an implantable electrical stimulation device provided by an embodiment of the present invention.

[0032] Figure 12 A structural schematic diagram of an implantable electrical stimulation device provided by an embodiment of the present invention. Detailed implementation manners

[0033] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0034] Figure 1 A structural schematic diagram of an implantable electrical stimulation system 100 provided by an embodiment of the present invention. It should be noted that in Figure 1 , the reference numeral SC is used to indicate the spinal cord of the patient, and the reference numeral SK is used to indicate the skin of the patient. In addition, the implantable electrical stimulation system provided by the present invention can also be used for electrical stimulation treatment of other parts except the spinal cord, such as the brain, waist, legs, etc. This embodiment only takes the electrical stimulation system for the spinal cord as an example for illustration, and does not mean that the implantable electrical stimulation system provided by the present invention is limited to the spinal cord.

[0035] In order to avoid misstimulation of parts that do not need to be treated, achieve precise stimulation, and at the same time reduce battery consumption, as Figure 3 shown, in the related art, multiple electrode contacts on the electrode lead are designed to be equally spaced, that is, the electrode contacts between the same electrode contact group are not continuous, and there is a gap G.

[0036] In practical applications, when the posture of the patient's body changes (for example, from a lying position to a sitting position, from a sitting position to a standing position, or bending, squatting, coughing, etc.), there may be movement between the electrode contacts on the electrode lead and the nerve fibers of the body, thereby changing the contact part between the electrode contacts and the nerve fibers of the patient's body. For example, there may be a situation where part of the electrode contact contacts the nerve fibers of the patient's body, and the gap between the electrode contacts contacts the nerve fibers (that is, the electrode contacts do not contact the nerve fibers). Correspondingly, the degree to which the electrical stimulation pulse actually acts on the nerve fibers of the patient's body will also change. If the previous electrode contacts are always used for electrical stimulation, under the same electrical stimulation pulse intensity, if the above-mentioned situation of poor contact between the electrode contacts and the patient's body occurs, it may cause insufficient stimulation, resulting in a weakened treatment effect and the patient's body symptoms cannot be effectively relieved.

[0037] In view of the above problems, the present invention creatively proposes to judge the contact situation between the electrode contacts and the patient's body according to the impedance value between the electrode contacts, and further combines the characteristic values of the ECAP waveform to timely switch the electrode contacts to output electrical stimulation pulses when the contact is poor, so as to achieve precise stimulation.

[0038] The following will refer to the attached Figures 1 - 12 to specifically introduce various non-limiting embodiments of the present invention.

[0039] As Figure 1 shown, the implantable electrical stimulation system 100 includes an electrode lead 10 and an implantable electrical stimulation device 20. As Figure 2 shown, the implantable electrical stimulation device 20 includes: a controller 21, a stimulation circuit 22, a collection circuit 23, a switching circuit 24, and an impedance detection device 25.

[0040] The electrode lead 10 is configured to be implanted into the patient's body, and deliver electrical stimulation pulses (including treatment pulses and evoked pulses) to the patient's body through the electrode contacts on the electrode lead 10, such as the electrode contact 11a1. The controller 21 can be configured to be implanted into the patient's body or can be configured to be located outside the patient's body, and is used to generate electrical stimulation pulses. The controller 21 can be electrically connected to the electrode lead 10 through the switching circuit 24, and deliver the electrical stimulation pulses to the patient's body through the electrode lead 10 to achieve the purpose of treatment. The impedance detection device 25 is electrically connected to the controller and can be configured to measure the impedance of the patient's body (biological tissue, such as nerve fibers) located between the electrode contacts of the implantable electrical stimulation device.

[0041] The switch circuit 24 is connected between the controller 21 and the electrode lead 10, and is configured to conduct and disconnect the circuit between the electrode lead and the electrode contact under the control of the controller 21, so as to switch different electrode contacts to output electrical stimulation pulses when there is a problem with the contact between the current electrode contact and the body.

[0042] The acquisition circuit 23 is electrically connected to the controller and is configured to receive the evoked compound action potential (ECAP) signal generated by the body stimulated by the electrical stimulation pulse emitted by the stimulation circuit 22 after the controller controls the stimulation circuit and the acquisition circuit to be conducted with the corresponding electrode contacts.

[0043] The controller 21 can precisely control the conduction of any electrode contact with the stimulation circuit and the acquisition circuit by controlling the switch circuit 24, without setting too many channels in the controller, which helps to reduce the volume of the controller. This design enables the controller to flexibly control the electrode contacts only by controlling the switch circuit, and the number of channels of the switch circuit can be flexibly designed according to the number of channels of the controller and the number of electrode contacts, so as to achieve precise control of a single electrode contact, which is more convenient. In addition, the implementation method of the switch circuit is relatively simple, which is beneficial to reducing the manufacturing cost of the implantable nerve stimulation device.

[0044] Exemplarily, as Figure 1 shown, the implantable electrical stimulation system 100 provided by an embodiment of the present invention can be used for electrical stimulation treatment of the spinal cord. Among them, the electrode lead 10 is adapted to be placed in the spinal canal of the body to contact the spinal nerves of the body. By implanting the electrode lead 10 into the spinal canal of the body, the length direction of the electrode lead 10 can be substantially parallel to the spinal cord SC, as close as possible to the spinal nerves, so as to improve the effect of electrical stimulation.

[0045] Figure 3 is a schematic structural diagram of the electrode lead 10. In Figure 3 it, the arrow L can be used to indicate the length direction of the electrode lead 10, and the arrow A can be used to indicate the longitudinal direction perpendicular to the length direction. Figure 4 is Figure 3 a cross-sectional view taken along the longitudinal direction (A direction).

[0046] In some embodiments, as Figure 3 and Figure 4 shown, the electrode lead 10 may include a plurality of electrode contact groups 11 (11a, 11b, 11c, 11d, 11e, 11f, 11g, 11h), and the plurality of electrode contact groups 11 are spaced apart along the length direction of the electrode lead 10. Each electrode contact group includes three electrode contacts (for example, 11a1, 11a2, 11a3). In one example, the three electrode contacts may be located on the same circular ring.

[0047] In some embodiments, the controller 21 can stimulate the human body through two electrode contacts of the same electrode contact group. As Figure 3 shown, the electrode lead 10 can include electrode contacts 11a1 and 11a2, which are configured to stimulate the human body. For example, it can be the spinal cord SC of the human body or other parts of the human body, which is not specifically limited here. The stimulation circuit 22 is configured to generate a first pulse signal and apply the first pulse signal to the first electrode contact to stimulate the human body.

[0048] In some embodiments, the controller 21 can also send treatment pulses to the patient's body through the electrode contacts in at least two electrode contact groups among the multiple electrode contact groups 11 (such as Figure 3 11a1 and 11b1 shown), and send evoked pulses to the patient's body through the electrode contacts in at least two electrode contact groups among the multiple electrode contact groups (which can be 11a1 and 11b1, or other electrode contacts, such as 11d1, 11e1, etc.).

[0049] In some embodiments, the controller 21 is also configured to collect ECAP signals through the electrode contacts in the multiple electrode contact groups 11.

[0050] It should be noted that Figure 3 in the embodiments shown, only as an example, 8 electrode contact groups are shown, and each electrode contact group includes 3 electrode contacts, which is not used to limit the number of electrode contact groups and the number of electrode contacts included in the electrode contact group. The electrode lead 10 can also include other numbers of electrode contact groups 11. For example, it can include 2, 3, 6, etc. Figure 4 The number of electrode contacts in each electrode contact group shown can also be other numbers, which are not specifically limited here.

[0051] In some embodiments, the switch circuit can connect the electrode contacts to different circuits according to the instructions of the controller to perform function switching of the electrode contacts and conduction and disconnection of the electrode contacts. For example, the electrode contacts can deliver or stop delivering electrical stimulation pulses, such as treatment pulses or evoked pulses, etc. It should be understood that the present invention does not limit the implementation manner of the function switching of the electrode contacts.

[0052] The treatment pulse is used to treat the symptoms of the body, such as relieving the pain of the body. Therefore, its stimulation parameter values (including other parameters except the amplitude and pulse width of the pulse, such as frequency) need to meet the requirement that the treatment pulse can effectively relieve the symptoms of the body at the treatment site to achieve the treatment effect. The evoked pulse is used to stimulate the ECAP signal, so its stimulation parameter values only need to meet the requirement that the nerve fibers of the body can emit ECAP signals and may not participate in the treatment effect.

[0053] In the present invention, the electrical stimulation pulses (including therapeutic pulses and / or evoked pulses) may refer to current pulses or voltage pulses, and the stimulation intensity can be adjusted by adjusting the stimulation parameter values of the electrical stimulation pulses. Specifically, the stimulation parameter values may include the amplitude of the pulses and / or the pulse width of the pulses.

[0054] In the implantable electrical stimulation system provided by the present invention, the contact situation between the electrode contacts and the patient's body can be determined according to the result of comparing the impedance value of the patient's body located between the electrode contacts detected in real time by the impedance detection device with the threshold value (the impedance range when the electrode contacts are in normal contact), so as to timely switch different electrode contacts to output electrical stimulation pulses when the contact between the electrode contacts and the patient's body is poor, so as to achieve precise stimulation of the treatment site.

[0055] Corresponding to the above system, the present invention provides a control method for an implantable electrical stimulation device 20 applied to the above system. Figure 5 The following is a schematic flowchart of the control method of the implantable electrical stimulation device provided by an exemplary embodiment of the present invention.

[0056] In some embodiments, Figure 5 The method shown can be executed by a controller.

[0057] As Figure 5 shown, the method may include the following steps:

[0058] S210. Obtain the characteristic value of the waveform of the ECAP signal of the patient's body in the current posture.

[0059] In some embodiments, therapeutic pulses and evoked pulses can be sent to the patient's body through the electrode contacts in two electrode contact groups among the multiple electrode contact groups 11. For example, the first electrode contact in the first electrode contact group and the second electrode contact in the second electrode contact group can be used to send electrical stimulation pulses to the patient's body at different positions and directions through the electrode contacts on the electrode leads, and more diverse treatment schemes can be realized by assigning different functions to the electrode contacts in the multiple electrode contact groups.

[0060] Exemplarily, the first electrode contact and the second electrode contact can be two electrode contacts in adjacent electrode contact groups among the multiple electrode contact groups. For example, as Figure 3 shown, the first electrode contact and the second electrode contact can be electrode contacts 11a1 and 11b1 respectively. The first electrode contact can be used to send positive-phase pulses, and the second electrode contact can be used to send negative-phase pulses; or the second electrode contact can be used to send positive-phase pulses, and the first electrode contact can be used to send negative-phase pulses, which is not specifically limited herein.

[0061] In some embodiments, it is also possible to sense the ECAP signal emitted by the nerve fibers of the patient's body after the acquisition electrode contact senses the induced pulse emitted by the first electrode contact or the second electrode contact, and ensure a certain distance between the first electrode contact and / or the second electrode contact and the acquisition electrode contact. That is, the ECAP signal is acquired at a position far from the position where the therapeutic pulse and / or the induced pulse is emitted. For example, as Figure 3 shown, the acquisition electrode contact can be 11d1. Based on this, it is possible to better balance the degree to which the ECAP signal is affected by the stimulus pulse tail and the degree of distortion of the ECAP signal during long-distance transmission, so as to acquire a more effective ECAP signal and the waveform of the ECAP signal, and improve the accuracy of electrical stimulation regulation.

[0062] In some embodiments, in order to facilitate the subsequent use of the waveform of the ECAP signal, the preprocessed ECAP signal can be normalized. Exemplarily, based on a deep learning algorithm, the eigenvalue of the waveform of the ECAP signal can be extracted. Among them, the eigenvalue of the waveform of the ECAP signal usually includes the peak value P1, the peak value P2, and the valley value N1.

[0063] S220. Real-time measure the first impedance value between the first electrode contact and the second electrode contact on the electrode lead of the implantable electrical stimulation device.

[0064] The first impedance value can be the actual impedance of the patient located between the two electrode contacts delivering the electrical stimulation pulse in real time. For example, the impedance value of the patient's body located between the first electrode contact and the second electrode contact.

[0065] In some embodiments, considering that the patient's posture may change continuously, if only one measured impedance value is used as the reference value, it may affect the accuracy of the impedance value judgment. Exemplarily, based on the impedance values of 5 groups (including the current moment) before and after the current impedance value moment, the average value can be obtained as the first impedance value, so that the first impedance value is more accurate and more in line with the actual requirements.

[0066] S230. Determine the contact situation between the first electrode contact and the second electrode contact and the patient's body based on the first impedance value.

[0067] The contact condition can be the connection condition between the electrode contact for delivering electrical stimulation and the part of the patient to be stimulated (treatment part). Specifically, the contact condition can be classified into good contact, partial contact, and non-contact. To a certain extent, the contact condition between the electrode contact and the patient's body can reflect the probability (proportion) of the electrical stimulation pulses emitted in the electrode lead that can be delivered to the patient's body. For example, when the contact area between the electrode contact and the patient's body (treatment part) accounts for 90% of the electrode contact area, generally it can be considered that 90% of the electrical stimulation pulses emitted by the electrode contact are delivered to the treatment part.

[0068] In some embodiments, the contact condition between the current electrode contact and the patient's body can be determined according to the impedance value (first impedance value) of the patient's body located between the electrode contacts for delivering electrical stimulation pulses. The specific determination process can refer to Figure 6 and the related description.

[0069] S240. Determine whether to switch different electrode contacts to output pulses according to the contact condition and the characteristic values of the waveform of the above-mentioned ECAP signal.

[0070] Considering that nerve fibers generally have a certain tolerance range for electrical stimulation pulses, that is, within a certain range of changes in the magnitude of electrical stimulation, it is considered that the electrical stimulation is applicable to the patient and does not need to be adjusted. Therefore, when it is determined in step S230 that the contact condition between the first electrode contact and the second electrode contact and the patient's body is poor, the characteristic values of the waveform of the ECAP signal can be used to determine whether the current stimulation is within the tolerance range of the patient, and then determine whether to switch different electrode contacts to output electrical stimulation pulses and adjust the corresponding stimulation parameter values, so as to achieve precise stimulation, ensure the treatment effect while reducing the frequency of switching electrode contacts and reducing energy consumption. The specific contact condition determination process can refer to Figures 6 - 9 and its related description.

[0071] Specifically, in some embodiments, the aforementioned S240 may include the following sub-steps:

[0072] S241. When the first impedance value is greater than the second threshold, determine to switch different electrode contacts to deliver pulses.

[0073] S242. When the first impedance value is greater than the first threshold and less than the second threshold, compare the characteristic value with the third threshold, and when the characteristic value is greater than the third threshold, determine to switch different electrode contacts to deliver pulses.

[0074] In some embodiments, the third threshold can be set, where the third threshold can be understood as the deviation range (i.e., the sensitivity range of the ECAP waveform) of the waveform of the ECAP signal that the patient's body can tolerate and accept.

[0075] In some embodiments, the eigenvalue of the waveform of the ECAP signal in the current posture can be obtained, and the difference between the eigenvalue of the waveform of the currently obtained ECAP signal and the eigenvalue of the waveform of the target ECAP signal (the waveform of the ECAP signal fed back under the optimal stimulation parameters) can be calculated. For the specific method of obtaining the waveform of the target ECAP signal, reference can be made to the related art and will not be elaborated here. After obtaining the difference, the difference is compared with a third threshold. When the difference exceeds the third threshold, it is considered that the stimulation pulse output based on the current electrode contact makes the patient uncomfortable and has affected the treatment effect, and it is determined that different electrode contacts need to be switched to output the electrical stimulation pulse. Otherwise, it is considered that the current stimulation is still within the tolerance range of the patient, the patient can be comfortable, the treatment effect is not affected, and there is no need to switch the electrode contact.

[0076] S250. In the case of determining to switch different electrode contacts, switch to the third electrode contact and the fourth electrode contact to deliver pulses to the body.

[0077] In some embodiments, the third electrode contact and the fourth electrode contact can be electrode contacts in the same electrode contact group as the first electrode contact and the second electrode contact. Among them, the third electrode contact and the fourth electrode contact can be the same as or different from the first electrode contact and the second electrode contact.

[0078] In some embodiments, the impedance value between the body of other electrode contacts in the electrode contact group where the electrode contacts (the first electrode contact and the second electrode contact) for currently outputting the electrical stimulation pulse are located on the patient can be obtained, and based on the difference between this impedance value and a preset threshold, the third electrode contact and the fourth electrode contact, that is, the electrode contacts currently suitable for delivering the electrical stimulation pulse, can be determined.

[0079] Exemplarily, as Figure 3 shown, if the electrode contacts for currently outputting the electrical stimulation pulse are 11a1 and 11b1, when it is determined that the electrode contact 11a1 has poor contact with the patient's body, the impedance values between the electrode contact 11a2 and the electrode contact 11b1, and between the electrode contact 11a2 and the electrode contact 11b1 in the electrode contact group 11a can be measured respectively, and the respectively measured impedance values are compared with a first threshold to determine the electrode contact currently in contact with the patient's body.

[0080] Considering that there may be a situation where only the first electrode contact has poor contact with the patient's body, in this case, the fourth electrode contact can be understood as the second electrode contact, that is, the second electrode contact is not switched. Similarly, when only the second electrode contact has poor contact with the patient's body, the third electrode contact can be understood as the first electrode contact.

[0081] In some embodiments, considering that the current stimulation parameter values may not be applicable to the patient after switching to a new electrode contact, in some embodiments, the difference between the characteristic value of the current ECAP waveform and the second threshold may be calculated, and then, based on the stimulation parameter value function, the stimulation parameter values may be adjusted in combination with this difference to make the patient comfortable. The specific adjustment process may refer to the related art.

[0082] In some embodiments, the stimulation parameter value function may be a linear function, a polynomial function, or a piecewise function, which is not specifically limited herein.

[0083] In some embodiments, the measured voltage value between the first electrode contact and the second electrode contact may be measured, and at the same time, the measured current value between the first electrode contact and the second electrode contact may be measured, and then the impedance value between the first electrode contact and the second electrode contact may be obtained based on the measured voltage value and the measured current value.

[0084] To improve the accuracy of the measurement results, the amplitude of the preset voltage may be adjusted, and the amplitude between the first electrode contact and the second electrode contact may be repeatedly measured.

[0085] According to the implantable electrical stimulation device provided by the embodiments of the present invention, the impedance value of the body between the electrode contacts delivering the therapeutic pulses on the electrode leads of the implantable electrical stimulation device of the patient is measured in real time by the impedance detection device, the measured actual impedance value is compared with the threshold value, the contact condition between the electrode contact and the body of the patient is further determined, and whether to switch different electrode contacts to output pulses is determined according to the contact condition and the characteristic value of the waveform of the ECAP signal in the current posture. Thus, when the electrode contact is twisted and the contact with the body of the patient is poor, it is timely switched to a suitable electrode contact to output pulses, so as to achieve precise stimulation of the treatment site and ensure the accuracy of the treatment process and the treatment effect.

[0086] To further elaborate on the process of determining the contact condition between the electrode contact and the body of the patient, the present invention also provides a method for determining the contact condition between the electrode contact and the body of the patient.

[0087] Figure 6 It is a schematic flowchart of a method for determining the contact condition between the electrode contact and the body of the patient provided by an exemplary embodiment of the present invention. In some embodiments, Figure 6 The method shown may be executed by a controller.

[0088] As Figure 6 shown, the method may include the following steps:

[0089] S310. Compare the first impedance value with the first threshold.

[0090] S320. When the first impedance value exceeds the first threshold, it is determined that at least one of the first electrode contact and the second electrode contact has poor contact with the body.

[0091] Specifically, S320 may include the following sub-steps:

[0092] S321. When the first impedance value is greater than the second threshold, it is determined that at least one of the first electrode contact and the second electrode contact is not in contact with the body.

[0093] S322. When the first impedance value is greater than the first threshold and less than the second threshold, it is determined that at least one of the first electrode contact and the second electrode contact is in partial contact with the body, and at the same time, one of the other electrode contacts in the corresponding electrode contact group is in partial contact with the body.

[0094] During the process of the patient's posture changing, the electrode contacts twist relative to the patient's body, causing the contact part between the electrode contacts and the patient's body to change, resulting in poor contact. This poor contact may have various contact situations. To more clearly compare the situations of good contact and poor contact, the present invention provides Figure 3 a schematic structural diagram of three contact situations between the electrode contacts and the patient's body taking the electrode contact group 11a in Figures 7 - 9 as an example (

[0095] Figure 7 is a schematic structural diagram of good contact between the electrode contacts and the patient's body. Figures 7 - 8 is a schematic structural diagram of poor contact between the electrode contacts and the patient's body. Exemplarily, the situation of poor contact may be that at least one of the first electrode contact and the second electrode contact is in partial contact with the patient's body. Specifically, as Figure 7 shown, the first electrode contact or the second electrode contact is in partial contact with the patient's body. Compared with Figure 7 , the contact area between the electrode contacts and the patient's body becomes smaller; as Figure 9 stated, it is also possible that the first electrode contact or the second electrode contact is in partial contact with the patient's body, and at the same time, one of the other electrode contacts in the corresponding electrode contact group is in partial contact with the patient's body (that is, two electrode contacts in the same electrode contact group are in partial contact with the patient's body); it is also possible that the amplitude of the twist between the electrode contacts and the patient's body is relatively large, resulting in a situation where the electrode contacts are not in contact with the patient's body.

[0096] To further determine that the poor contact between the electrode contacts and the nerve fibers of the body is partial contact (such as Figure 8 and Figure 9Whether it is in contact or not as shown), a first threshold and a second threshold can be set. Among them, the first threshold can be used to determine whether the electrode contact is in contact with the body part, and the second threshold can be used to determine whether the electrode contact is in contact with the body. Specifically, the specific values can be determined through preliminary tests (i.e., the actual feedback of the patient).

[0097] Specifically, the first impedance value can be compared with the first threshold first. If the first impedance value is greater than the first threshold, it is considered that the contact between the first electrode contact and the second electrode contact with the patient's body is poor. Then, the first impedance value is further compared with the second threshold. When the first impedance value is greater than the second threshold, it is determined that there is a situation where the electrode contact is open-circuited with the body in the first electrode contact and the second electrode contact, that is, not in contact. When the first impedance value is less than the second threshold (i.e., the first impedance value is between the first threshold and the second threshold), it is determined that there is a situation where the electrode contact is in partial contact with the body in the first electrode contact and the second electrode contact, that is, ( Figure 8 、 Figure 9 the situation shown). Considering that there may be errors in the actual application process, a 5% floating range, that is, an error range, can be allowed during the comparison to improve the accuracy of the judgment.

[0098] Exemplarily, the second threshold can be 4 kΩ (ohms), and the first threshold can be 25% of the second threshold, 1 kΩ (ohms). Correspondingly, if the measured first impedance value is greater than 4 kΩ, it is considered that the first electrode contact and the second electrode contact are not in contact with the body; if the first impedance value is greater than 1 kΩ and less than 4 kΩ, it is considered that the first electrode contact and the second electrode contact are in partial contact with the body.

[0099] In some embodiments, when it is detected that the first electrode contact and the second electrode contact are less than 50 Ω (ohms), it can be directly determined that a short circuit occurs between the two electrode contacts.

[0100] After determining the contact situation between different electrode contacts and the patient's body, for different contact situations, it may be necessary to determine the specific electrode contact with poor contact. The present invention also provides a method for determining the electrode contact with poor contact.

[0101] Figure 10 It is a schematic flowchart of a method for adjusting the electrode contact for outputting a therapeutic pulse provided by an exemplary embodiment of the present invention. In some embodiments, Figure 10 the method shown can be executed by a controller.

[0102] As Figure 11 shown, the method may include the following steps:

[0103] S410. Measure the second impedance value between the first electrode contact and the fifth electrode contact on the electrode lead of the implantable electrical stimulation device.

[0104] S420. Compare the second impedance value with a first threshold.

[0105] S430. When the second impedance value is not greater than the first threshold, determine that the contact between the second electrode contact and the patient's body is poor.

[0106] S440. When the second impedance value is greater than the first threshold, measure the third impedance value between the second electrode contact and the fifth electrode contact on the electrode lead of the implantable electrical stimulation device.

[0107] S450. Compare the third impedance value with the first threshold to determine whether the third impedance value exceeds the first threshold.

[0108] S460. When the third impedance value is not greater than the first threshold, determine that the contact between the first electrode contact and the body is poor.

[0109] S470. When the third impedance value is greater than the first threshold, determine that both the first electrode contact and the second electrode contact are in poor contact with the body.

[0110] The fifth electrode contact can be an electrode contact in an electrode contact group different from the electrode contact group where the first electrode contact and the second electrode contact are located.

[0111] The second impedance value can be the actual impedance value of the patient's body between the first electrode contact and the fifth electrode contact. Correspondingly, the third impedance value is the actual impedance value of the patient's body between the second electrode contact and the fifth electrode contact on the electrode lead.

[0112] Since the distance to a certain extent also affects the impedance value, the fifth electrode contact can be selected from the electrode contact group adjacent to the first electrode contact group. Exemplarily, if the first electrode contact is an electrode contact in electrode contact group 11b, then an electrode contact in electrode contact group 11c can be selected as the fifth electrode contact as the reference electrode contact to reduce errors. For the specific process of determining the contact situation according to the impedance value, reference can be made to Figures 6 - 9 and the relevant description, which will not be elaborated here.

[0113] Figure 11 It is a schematic diagram of the system module of a control device of an implantable electrical stimulation device provided by some embodiments of the present application.

[0114] As Figure 10 shown, the control output pulse device 500 of the implantable electrical stimulation device may include an acquisition module 510, a measurement module 520, a determination module 530, and a switching module 540.

[0115] The acquisition module 510 can be used to acquire the eigenvalue of the waveform of the ECAP signal of the patient's body in the current posture.

[0116] The measurement module 520 can be used to measure the first impedance value between the first electrode contact and the second electrode contact on the electrode lead of the implantable electrical stimulation device in real time, where the first impedance value is the actual impedance value of the patient's body between the first electrode contact and the second electrode contact, and the electrode contact groups where the first electrode contact and the second electrode contact are located are different and used to output pulses.

[0117] The determination module 530 can be used to determine the contact conditions of the first electrode contact and the second electrode contact with the patient's body based on the first impedance value, and determine whether to switch to different electrode contacts to output pulses according to the contact conditions and the eigenvalue;

[0118] The switching module 540 can be used to switch to the third electrode contact and the fourth electrode contact to deliver pulses to the body when it is determined to switch to different electrode contacts to output pulses.

[0119] In some embodiments, the measurement module 520 can also be used to measure the measured voltage value between the first electrode contact and the second electrode contact; measure the measured current value between the first electrode contact and the second electrode contact; and obtain the impedance value between the first electrode contact and the second electrode contact based on the measured voltage value and the measured current value.

[0120] In some embodiments, the acquisition module is used to acquire the eigenvalue of the waveform of the ECAP signal in the current posture, calculate the difference between the eigenvalue of the waveform of the currently acquired ECAP signal and the eigenvalue of the waveform of the target ECAP signal (the waveform of the ECAP signal fed back under the optimal stimulation parameters), and the determination module 530 is used to compare the difference with the third threshold (the range that the patient can tolerate), which can be understood as the sensitivity range of the ECAP signal waveform. If the difference exceeds the third threshold, then the switching module 540 is used to switch to different electrode contacts to output electrical stimulation pulses and adjust the stimulation parameter value accordingly to achieve precise stimulation, ensure the treatment effect while reducing the frequency of switching electrode contacts and reducing energy consumption.

[0121] In some embodiments, the determination module 530 can also be used to determine to switch to different electrode contacts to output pulses when at least one of the first electrode contact and the second electrode contact does not contact the patient's body; when at least one of the first electrode contact and the second electrode contact partially contacts the patient's body and at the same time one of the other electrode contacts in the corresponding electrode contact group partially contacts the patient's body, compare the eigenvalue with the third threshold.

[0122] In some embodiments, the determination module 530 may be used to compare a first impedance value with a first threshold; when the first impedance value is greater than the first threshold, it is determined that at least one of the first electrode contact and the second electrode contact has poor contact with the patient's body.

[0123] In some embodiments, the determination module 530 may also be used to measure a second impedance value between a first electrode contact and a fifth electrode contact on the electrode lead of the implantable electrical stimulation device, where the second impedance value is the actual impedance value of the patient's body between the first electrode contact and the fifth electrode contact, and the first electrode contact and the fifth electrode contact are in different electrode contact groups for outputting pulses; compare the second impedance value with the first threshold; when the second impedance value is not greater than the first threshold, it is determined that the second electrode contact has poor contact with the body; when the second impedance value is greater than the first threshold, measure a third impedance value between a second electrode contact and a fifth electrode contact on the electrode lead of the implantable electrical stimulation device, where the third impedance value is the actual impedance value of the patient's body between the second electrode contact and the fifth electrode contact, and the second electrode contact and the fifth electrode contact are in different electrode contact groups for outputting pulses; compare the third impedance value with the first threshold; when the third impedance value is not greater than the first threshold, it is determined that the first electrode contact has poor contact with the body; when the third impedance value is greater than the first threshold, it is determined that both the first electrode contact and the second electrode contact have poor contact with the body.

[0124] It should be understood that the specific working processes and functions of the acquisition module 510, the measurement module 520, the determination module 530, and the switching module 540 in the above embodiments may refer to the description in the control method of the implantable electrical stimulation device provided in the above Figures 5 - 10 embodiment. To avoid repetition, it will not be elaborated here.

[0125] Figure 12 An implantable electrical stimulation device 600 provided by an embodiment of the present application includes: a processor 610 and a storage medium 620, where a program is stored in the storage medium 620, and when the program is executed by the processor 610, the processor 610 is caused to execute the method for controlling the implantable electrical stimulation device to output pulses provided in the above embodiment.

[0126] An embodiment of the present disclosure also provides a storage medium, in which a program is stored, and when the program is executed by a processor, the processor is caused to execute the method for controlling the implantable electrical stimulation device to output pulses provided in the above embodiment.

[0127] It should be understood that the term "including" and its variants used in the present disclosure are open-ended, that is, "including but not limited to". The term "one embodiment" means "at least one embodiment", and the term "another embodiment" means "at least one additional embodiment".

[0128] It should be noted that the various specific technical features (elements) described in the above specific embodiments can be combined in any suitable manner without conflict. To avoid unnecessary repetition, this disclosure will not separately describe various possible combination methods.

[0129] Those of ordinary skill in the art can realize that the units or modules of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of this disclosure.

[0130] In several embodiments provided by this disclosure, it should be understood that the disclosed systems and devices can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units or modules is only a logical function division, and there can be other division methods in actual implementation. For example, multiple units or modules can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed coupling or direct coupling or communication connection to each other can be through some interfaces. The indirect coupling or communication connection of the units or modules can be in an electrical or other form.

[0131] In addition, the functional units or modules in each embodiment of this disclosure can be integrated in a processing unit or module, or each unit or module can exist physically alone, or two or more units or modules can be integrated in one unit or module.

[0132] As described above, the above is only the specific embodiment of this disclosure, but the protection scope of this disclosure is not limited thereto. Any person skilled in the art within the technical scope disclosed by this disclosure can think of changes or substitutions, which should be covered within the protection scope of this disclosure. Therefore, the protection scope of this disclosure should be subject to the protection scope of the claims.

Claims

1. An implantable electrical stimulation device, comprising: A controller, An impedance detection device, connected to the controller, for detecting the impedance value between electrode contacts; A stimulation circuit, configured to generate pulses and output the pulses through the electrode contacts on the electrode lead; A switch circuit, connected between the controller and the electrode lead, configured to conduct the electrode contacts with the stimulation circuit under the control of the controller to switch different electrode contacts to output pulses; An acquisition circuit, electrically connected to the controller, configured to receive the evoked compound action potential ECAP signal generated by the pulses emitted by the stimulation circuit to stimulate the patient's body after the controller controls the stimulation circuit and the acquisition circuit to conduct with the electrode contacts, wherein the controller is configured to perform the following steps: Obtain the characteristic value of the waveform of the ECAP signal of the patient's body in the current posture; Measure in real time the first impedance value between the first electrode contact and the second electrode contact on the electrode lead of the implantable electrical stimulation device through the impedance detection device, wherein the first impedance value is the actual impedance value of the patient's body located between the first electrode contact and the second electrode contact, and the first electrode contact and the second electrode contact are in different electrode contact groups for outputting pulses; Determine the contact condition between the first electrode contact and the second electrode contact and the body based on the first impedance value; Determine whether to switch different electrode contacts to output the pulses according to the contact condition and the characteristic value; and In the case of determining to switch different electrode contacts, switch to the third electrode contact and the fourth electrode contact through the switch circuit to deliver the pulses to the body, wherein determining whether to switch different electrode contacts to output the pulses according to the contact condition and the characteristic value includes: When the first impedance value is greater than the second threshold, determine to switch different electrode contacts to deliver the pulses; When the first impedance value is greater than the first threshold and less than the second threshold, compare the characteristic value with the third threshold, and when the characteristic value is greater than the third threshold, determine to switch different electrode contacts to deliver the pulses.

2. The implantable electrical stimulation device according to claim 1, wherein, The determining the contact condition between the first electrode contact and the second electrode contact and the body based on the first impedance value includes: Compare the first impedance value with the first threshold; When the first impedance value is greater than the first threshold, determine that at least one of the first electrode contact and the second electrode contact is in poor contact with the body.

3. The implantable electrical stimulation device according to claim 2, wherein When the first impedance value is greater than the first threshold, determining that at least one of the first electrode contact and the second electrode contact is in poor contact with the body includes: When the first impedance value is greater than the first threshold and less than the second threshold, it is determined that at least one of the first electrode contact and the second electrode contact partially contacts the body, or at least one of the first electrode contact and the second electrode contact partially contacts the body while one of the other electrode contacts in the corresponding electrode contact group partially contacts the body; When the first impedance value is greater than the second threshold, it is determined that at least one of the first electrode contact and the second electrode contact does not contact the body.

4. The implantable electrical stimulation device according to claim 1, wherein, Said switching different electrode contacts to deliver the pulse includes: Determining a new electrode contact for outputting the pulse according to the impedance values of the other electrode contacts in the electrode contact group where the electrode contact currently outputting the pulse is located; Switching the electrode contact currently outputting the pulse to the new electrode contact for outputting the pulse.

5. The implantable electrical stimulation device according to claim 1, wherein The controller is further configured to: Measure a second impedance value between the first electrode contact and the fifth electrode contact on the electrode lead of the implantable electrical stimulation device through the impedance detection device, wherein the second impedance value is the actual impedance value of the patient's body between the first electrode contact and the fifth electrode contact, and the first electrode contact and the fifth electrode contact are in different electrode contact groups for outputting pulses; Compare the second impedance value with the first threshold; When the second impedance value is not greater than the first threshold, it is determined that the second electrode contact has poor contact with the body.

6. The implantable electrical stimulation device according to claim 5, wherein, The controller is further configured to: When the second impedance value is greater than the first threshold, measure a third impedance value between the second electrode contact and the fifth electrode contact on the electrode lead of the implantable electrical stimulation device through the impedance detection device, wherein the third impedance value is the actual impedance value of the patient's body between the second electrode contact and the fifth electrode contact, and the second electrode contact and the fifth electrode contact are in different electrode contact groups for outputting pulses; Compare the third impedance value with the first threshold; When the third impedance value is not greater than the first threshold, it is determined that the first electrode contact has poor contact with the body; When the third impedance value is greater than the first threshold, it is determined that both the first electrode contact and the second electrode contact have poor contact with the body.

7. The implantable electrical stimulation device according to claim 1, wherein, Said obtaining the characteristic value of the waveform of the ECAP signal of the patient's body in the current posture includes: Determining the waveform of the ECAP signal of the body in the current posture; Extracting the characteristic value of the waveform based on the deep learning algorithm.

8. The implantable electrical stimulation device according to claim 1, wherein Said measuring the first impedance value between the first electrode contact and the second electrode contact on the electrode lead of the implantable electrical stimulation device in real time through the impedance detection device includes: Measuring the measured voltage value between the first electrode contact and the second electrode contact; Measuring the measured current value between the first electrode contact and the second electrode contact; Obtaining the impedance value between the first electrode contact and the second electrode contact based on the measured voltage value and the measured current value.

9. A control device for an implantable electrical stimulation device, characterized in that, The device includes: An acquisition module configured to acquire the eigenvalue of the waveform of the ECAP signal of the patient's body in the current posture; A measurement module configured to measure in real time the first impedance value between a first electrode contact and a second electrode contact on the electrode lead of the implantable electrical stimulation device, where the first impedance value is the actual impedance value of the patient's body between the first electrode contact and the second electrode contact, and the first electrode contact and the second electrode contact are in different electrode contact groups for outputting pulses; A determination module configured to determine the contact situation between the first electrode contact and the second electrode contact and the body based on the first impedance value, and determine whether to switch to different electrode contacts to output the pulse according to the contact situation and the eigenvalue; A switching module: The switching module is configured to switch to a third electrode contact and a fourth electrode contact to deliver the pulse to the body when it is determined to switch to different electrode contacts to output the pulse, wherein the determination module is further configured to determine to switch to different electrode contacts to deliver the pulse when the first impedance value is greater than a second threshold; when the first impedance value is greater than a first threshold and less than a second threshold, compare the eigenvalue with a third threshold, and determine to switch to different electrode contacts to deliver the pulse when the eigenvalue is greater than the third threshold.

10. An implantable electrical stimulation system, characterized in that, It includes: The implantable electrical stimulation device according to any one of claims 1 to 8; An electrode lead connected to the implantable electrical stimulation device for delivering pulses to the patient's body.

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