Systems, methods, and devices for determining implant depth and producing an indication related to the determined depth

Abstract

A medical device may determine the depth of an implantable medical device within a patient body and may provide an indication of the depth. In one instance, the medical device may include a recharger for the implantable medical device. In another instance, a surgeon may use the medical device to determine if the implantable medical device is within a desired implant range within a patient body.

Description

SYSTEMS, METHODS, AND DEVICES FOR DETERMINING IMPLANT DEPTH AND PRODUCING AN INDICATION RELATED TO THE DETERMINED DEPTHTECHNICAL FIELD

[0001] This application claims priority from U.S. Provisional Patent Application 63 / 536,071 filed 31 August 2023, the entire content of which is incorporated herein by reference.

[0002] Embodiments relate to determining the depth of a medical implant. More particularly, embodiments relate to systems, methods, and devices that determine implant depth within the body of a patient and produce an indication related to the determined depth.BACKGROUND

[0003] To facilitate recharging, a rechargeable implantable medical device needs to be implanted within a certain range of depth within the body of a patient. When implanted too deep within the body of the patient, the medical device may not be able to charge properly. This improper charging may lead to a follow-on surgery to correct the position of the medical device within the body of the patient. This follow-on surgery may increase the trauma the patient experiences, increase the risk of complications, increase the cost of the treatment, and needlessly consume limited hospital resources, such as surgeons, operating rooms, and other staff required to support the surgeons.

[0004] As the implantable medical device’s implanted depth within the body of the patient is generally based upon the surgeon’s expertise and patient specific anatomical structures, there can be variations in how deep the medical device is implanted within the body of a patient. This variation could necessitate a follow-on surgery if the medical device is implanted too deeply within the body of the patient. The problem may be further exacerbated by tissue forming over time around the medical device, such as scar tissue, muscle, and fat.SUMMARY

[0005] Embodiments disclosed herein address issues such as these and others by determining a medical implant depth within a patient body and producing an indication related to the determined depth. The depth determination functionality and related components may be coupled with a recharger for an implantable medical device. A surgeon may use an external medical device, such as a recharger with the coupled depth determination functionality and components, during a procedure to determine the depth of an implantable medical device.

[0006] Embodiments provide systems, devices, and methods to provide a medical device including a depth sensing unit, a recharging unit, a user indicator unit, and a control unit. This includes the control unit coupled to the depth sensing unit, the recharging unit, and the user indicator unit. This also includes a memory and a processor, and the memory stores instructions that, when executed by the processor, causes the control unit to measure a first depth of an implantable medical device within a patient body with the depth sensor, produce an indication based on the first depth of the implantable medical device and a second depth, output, on the user indicator unit, the indication, and recharge the implantable medical device within the patient body using the recharging unit.

[0007] Embodiments provide systems, devices, and methods to provide for a surgeon to implant a medical device at a desired implant depth within a human body. This includes creating a pocket within the human body for the medical device, positioning the medical device within the pocket, and determining, using a depth finding medical device, the depth of the implantable medical device within the human body is within the desired implant depth. This also includes the pocket remaining open while the depth is being determined.DESCRIPTION OF THE DRAWINGS

[0008] FIG. 1 shows a typical environment for a medical system.

[0009] FIG. 2 shows an example of an external medical device.

[0010] FIG. 3 shows an example of the components of the external medical device.

[0011] FIG. 4 shows an example of logical operations that may be performed by the external medical device to measure the depth of an implantable medical device within a patient body and determine if the measured depth is within the desired implant depth.

[0012] FIG. 5 shows an example of logical operations that may be performed by a surgeon using an external medical device to implant an implantable medical device at a desired implant depth.DETAILED DESCRIPTION

[0013] Embodiments provide for the determination of an implantable medical device’s depth within a patient body and producing an indication based upon the depth. Embodiments further provide a method of determining the depth of an implantable medical device even at the time of implantation. Furthermore, embodiments provide for the determination of depth of the implantable medical device within the patient body using a recharging device that includes a depth sensing unit.

[0014] FIG. 1 shows a typical environment for medical system 100. In this example, medical system 100 may include external medical device 110 and implantable medical system 130 that is present within a patient body 120.

[0015] External medical device 110 may measure the depth of implantable medical system 130 within the patient body 120 and may include other functions, such as a power recharger for the implantable medical system 130. The external medical device 110 may be placed on the patient body 120, such as on the chest of the patient body 120 or another location that is in proximity to the implantable medical system 130. External medical device 110 may be placed on the bare skin of the patient body 120, over clothes on the patient body 120, over medical bandages on the patient body 120, combinations thereof, or any other material that may be between the patient body 120 and external medical device 110 that would allow the depth to be measured. External medical device 110 may compare the measured implant depth with a desired implant depth, such as by calculating the difference between the measured implant depth and the desired implant depth. The desired implant depth may be the depth that a surgeon desires to implant the implantable medical system 130 within the patient body 120. The desired implant depth may be defined by the manufacture of implantable medical system 130. The desired implant depth may be defined by a surgeon implanting the implantable medical system 130. The surgeon may be presented with the implant depth specified by the manufacturer and overwrite the desired implant depth based on the expertise of the surgeon. External medical device 110 may provide an indication if the measured implant depth is within the desired implant depth, such as by a sound and / or a display. The desired implant depthmay include a range of values, such as a minimum and maximum value. The desired implant depth may include a desired depth threshold. The desired implant depth may be based on the heat transfer function of a power recharger. In an example, external medical device 110 may include only the depth measuring functionality and related components. The external medical device 110 may be used to diagnose a charging issue due to the implantable medical system 130 being positioned too deep within the patient body 120.

[0016] The implantable medical system 130 of this example includes an implantable stimulation device 132 that has been implanted into a subcutaneous or subfascial pocket 140. At least one implantable medical lead 134, or lead and extension combination, is routed between a target stimulation site and the implantable stimulation device 132.

[0017] In this example, the implantable stimulation device 132 is an implantable neurostimulator (INS) configured for adaptive deep brain stimulation, as the lead 134 has a distal end 136 and distal electrodes 138 positioned within the brain at the target location for the stimulation to be applied. Other examples of implantable medical devices include but are not limited to neurostimulators for spinal cord stimulation where the lead 134 is directed to the spinal cord, peripheral nerve stimulation where the lead 134 is directed to a peripheral nerve, pelvic nerve stimulation where the lead 134 is directed to a pelvic nerve, cardiac stimulation where the lead 134 is directed to cardiac tissue, and the like. Implantable medical system 130 may communicate with the external medical device 110 via wired and / or wireless methods.

[0018] FIG. 2 shows an example of the external medical device 110. External medical device 110 may include depth sensing unit 210, recharging unit 220, control unit 230, and user indicator unit 240. Depth sensing unit 210 may determine the depth of implantable medical system 130 within the patient body 120. Recharging unit 220 may recharge implantable medical system 130. Control unit 230 may read from and / or control depth sensing unit 210 and recharging unit 220. Housing 250 may include depth sensing unit 210, recharging unit 220, control unit 230, and user indicator unit 240.

[0019] User indicator unit 240 may provide an indication regarding depth sensing unit 210 and recharging unit 220 as determined by control unit 230, such as the depth of implantable medical system 130 within the patient body 120 and / or the implantable medical system 130 recharging status. User indicator unit 240 may include a visual display, an audio producer, a tactile producer, combinations thereof, or any other component that can output an indication that is perceivable by a user. Furthermore, external medical device 110 may include controls, such as an on / off control, a standbymode control, a measure depth of implantable medical system 130 within the patient body 120 control, a silence an implant depth indication control, and the like.

[0020] Control unit 230 may base recharging implantable medical system 130 on the implantable medical system 130 depth within the patient body 120. For example, when implantable medical system 130 is implanted at a depth that exceeds a threshold, control unit 230 may control recharging unit 320 such that an excessive amount of heat is not generated. For another example, when implantable medical system 130 is implanted at a depth that exceeds a threshold, control unit 230 may adjust the charging time based on the depth. For an additional example, control unit 230 may adjust the charging efficiency of recharging unit 320 with regard to implantable medical system 130 based on the implantable medical system 130 depth within the patient body 120.

[0021] Though it is taught that depth sensing unit 210, recharging unit 220, control unit 230, and user indicator unit 240 are incorporated into the external medical device 110, these components may be distributed over any number of other devices that are configured to communicate. For example, user indicator unit 240 may be a separate device from another device that contains depth sensing unit 210, recharging unit 220, and control unit 230. For another example, a first device may include depth sensing unit 210, a second device may include recharging unit 220, and a third device may include user indicator unit 240. For an additional example, external medical device 110 may communicate with a computer to read from and control depth sensing unit 210 and recharging unit 220. Additionally or alternatively, recharging unit 220 may be removed from the external medical device 110. Additionally or alternatively, the recharging unit 220 may be replaced with one or more medical units, such as a heartbeat detector. Additionally or alternatively, functionality and components of depth sensing unit 210, recharging unit 220, control unit 230, and user indicator unit 240 may be combined and / or broken down into sub-components.

[0022] Potential advantages of combining depth sensing unit 210 and recharging unit 220 is that a surgeon may determine the depth of implantable medical system 130 during the implant surgery and / or the depth of implantable medical system 130 may be determined to facilitate addressing implantable medical system 130 charging issues.

[0023] FIG. 3 shows an example of the components of the external medical device 110. External medical device 110 may include depth sensing unit 310, recharging unit 320, control unit 330, and user indicator unit 340. Control unit 330 may include processor 334 and memory 332. The memory 332 may store instructions for theprocessor 334. Control unit 330 may include one or more processors. For example, control unit 330 may have a dedicated processor for separate functions, such as a first processor for depth sensing and a second processor for recharging. Each processor may be in the form of a general purpose programmable processor, an application specific processor, hardwired digital logic, combinations thereof, and the like.

[0024] Control unit 330 may use depth sensing unit 310 to determine the depth of implantable medical system 130 within the patient body 120. Depth sensing unit 310 may include an ultrasonic depth sensor. Potential advantages of using an ultrasonic depth sensor are that ultrasound may not harm the human body, ultrasound may not be regulated by a government body, and ultrasound may not interfere with wireless devices operating at radio frequencies. The ultrasonic depth sensor may include a piezoelectric crystal that when stimulated by an electrical signal may generate one or more ultrasound waves by mechanically vibrating the piezoelectric crystal. The ultrasound waves may then be reflected by the implantable medical system 130 and may be returned to depth sensing unit 310. The characteristics of the ultrasound waves and / or the returned ultrasound waves to depth sensing unit 310 may be used to determine the depth of implantable medical system 130 within the patient body 120 and other characteristics of the patient body 120, such as the types of tissue covering the implantable medical system 130. Ultrasound waves absorption and reflection may vary depending on the body part and the composition of the implantable medical system 130. In an example, established methodologies for determining the depth of an item of known construction may be used by control unit 230 to determine the depth of implantable medical system 130 within the patient body 120. For example, when the implantable medical system 130 construction includes metals, such as titanium, methodologies for determining the depth may include calibration based on the type of metal. The control unit 330 may determine the types of tissue between implantable medical system 130 and external medical device 110 based on the permittivity of the tissue. Control unit 330 may additionally or alternatively use a depth sensing unit 310 that includes an infrared sensor and / or a magnetic sensor that may be used to determine the depth of the implantable medical system 130 within the patient body 120.

[0025] After measuring the depth of implantable medical system 130 within the patient body 120, control unit 330 may determine if the depth is within a desired implant depth. For example, control unit 330 may compare the depth of implantable medical system 130 within the patient body 120 with a desired depth threshold. When the depthof implantable medical system 130 within the patient body 120 is less than or equal to the desired depth threshold, implantable medical system 130 may be determined to be implanted within the desired implant depth. When the depth of implantable medical system 130 within the patient body 120 is greater than the desired depth threshold, implantable medical system 130 may be determined to not be implanted within the desired implant depth. Additionally or alternatively, the difference between the depth of implantable medical system 130 within the patient body 120 and the desired depth threshold may be calculated. When the difference is less than or equal to zero, implantable medical system 130 may be determined to be implanted within the desired implant depth. When the difference is greater than zero, implantable medical system 130 may be determined to not be implanted within the desired implant depth.

[0026] Control unit 330 may create an indication by comparing the measured depth of the implantable medical system 130 within the patient body 120 with the desired depth threshold or desired implant depth. The indication may include one or more of the measured depth of the implantable medical system 130 within the patient body 120, the desired depth threshold, the amount the implantable medical system 130 depth is beyond the desired implant depth, the difference between the measured depth of the implantable medical device and the desired depth threshold or desired implant depth, whether the implantable medical system 130 is implanted within the desired implant depth or not, and the like. The indication may be communicated to a user of the external medical device 110. For example, the indication can be displayed on user indicator unit 340. The user indicator unit 340 may display the depth, the desired depth threshold, desired implant depth, the difference between the depth and the desired depth threshold, the difference between the depth and the desired implant depth, previous depth measurements, whether the implantable medical system 130 is implanted within the desired implant depth or not, and the like.

[0027] The user indicator unit 340 may include a visual indicator of whether the implantable medical system 130 is implanted within the desired implant depth or not. The visual indicator may include a bi-color light emitting diode (LED) that has a color when it is determined that implantable medical system 130 is implanted within the desired implant depth, such as a green color, and another color when it is determined that the implantable medical system 130 is not implanted within the desired implant depth, such as a red color. The visual indicator may include flashing to indicate whether it is determined that implantable medical system 130 is implanted within the desired implantdepth or not. The visual indicator may be constantly illuminated when it is determined that implantable medical system 130 is implanted within the desired implant depth and flashing when not. The visual indicator may have a variable illumination pulse width based on whether it is determined that implantable medical system 130 is implanted within the desired implant depth or not. For another example, the indication may be converted to a sound by a sound producing device included in user indicator unit 340. A sound may be played when it is determined that implantable medical system 130 is implanted within the desired implant depth, such as a short beep, and another sound may be played when it is determined that the implantable medical system 130 is not implanted within the desired implant depth, such as a long beep.

[0028] Control unit 330 may use recharging unit 320 to recharge implantable medical system 130. Recharging may be performed via wireless and / or wired methods. The recharging unit 320 may utilize a coil that inductively couples with a coil within the implantable medical device to wirelessly deliver energy to the implantable medical device for recharging the battery while the implantable medical device is implanted within the patient body 120.

[0029] Control unit 330 may operate depth sensing unit 310 and recharging unit 320 at different times and / or at different operating frequencies. Operating at different times and / or at different operating frequencies may help to reduce interference between depth sensing unit 310 and recharging unit 320. For example, when depth sensing unit 310 is an electromagnetic sensor, recharging unit 320 may be operated at a different frequency and / or time to facilitate reduction of interference between depth sensing unit 310 and recharging unit 320.

[0030] FIG. 4 shows an example of logical operations that may be performed by the external medical device to measure the depth of the implantable medical device within the patient body and determine if the measured depth is within the desired implant depth. In an example, external medical device 450 may include external medical device 110.

[0031] At step 410, the depth of an implantable medical system 130 may be measured. Step 410 may be performed by an external medical device 450. Furthermore, step 410 may be performed by depth sensing unit 310 and / or control unit 330 of the external medical device 110 described above.

[0032] At step 420, the desired implant depth may be received. Step 420 may be performed by external medical device 450. Furthermore, step 420 may be performed by control unit 330 and / or user indicator unit 340.

[0033] At step 430, a difference between the implanted depth and desired implant depth may be calculated. Step 430 may be performed by the external medical device 450. Furthermore, step 430 may be performed by the control unit 330.

[0034] At step 440, the difference between the implanted depth and desired implant depth may be displayed. Step 440 may be performed by external medical device 450. Furthermore, step 440 may be performed by control unit 330 and / or user indicator unit 340.

[0035] FIG. 5 shows an example of logical operations that may be performed by a surgeon using external medical device 550 to implant an implantable medical device at a desired implant depth. In an example, external medical device 550 may include external medical device 110.

[0036] At step 510, the surgeon may create a pocket within the patient body 120 for the implantable medical device. At step 520, the surgeon may position the implantable device within the pocket. At step 530, the surgeon may use a depth finding medical device, such as external medical device 110, external medical device 450, or external medical device 550, to determine if the depth of the implantable medical device is within the desired implant depth. Determining the depth of the implantable medical device is within the desired depth may be performed by depth sensing unit 310 and / or control unit 330. Once the depth of the implantable medical device is within the desired depth, the surgeon may close the pocket. In other words, the pocket remains open until the implantable medical device is within the desired depth.

[0037] While embodiments have been particularly shown and described, it will be understood by those skilled in the art that various other changes in the form and details may be made therein without departing from the spirit and scope of the invention.

Claims

What is claimed is:

1. A medical device comprising: a depth sensing unit; a recharging unit; a user indicator unit; and a control unit; wherein the control unit is coupled to the depth sensing unit, the recharging unit, and the user indicator unit; wherein the control unit includes a memory and a processor, and the memory stores instructions that, when executed by the processor, causes the control unit to: measure a first depth of an implantable medical device within a patient body with the depth sensing unit; produce an indication based on the first depth of the implantable medical device and a second depth; output, on the user indicator unit, the indication; and recharge the implantable medical device using the recharging unit.

2. The medical device of claim 1, wherein produce the indication further comprises: calculate a difference between the first depth and the second depth; and produce an indication based on the difference that includes at least one of the first depth, the second depth, and the difference between the first depth and the second depth.

3. The medical device of claim 1, wherein the depth sensing unit includes an ultrasonic depth sensor.

4. The medical device of claim 1, wherein the depth sensing unit includes at least one of an infrared sensor and a magnetic sensor.

5. The medical device of claim 1, wherein the second depth is a desired implant depth of the implantable medical device.

6. The medical device of claim 1, wherein the depth sensing unit and the recharging unit operate at different operating frequencies.

7. The medical device of claim 1, wherein the depth sensing unit and the recharging unit operate at different times.

8. The medical device of claim 2, wherein output the indication includes creating a sound with the user indicator unit.

9. The medical device of claim 8, wherein the sound is a first sound when the calculated difference is greater than or equal to zero, and the sound is a second sound when the calculated difference is less than zero.

10. The medical device of claim 2, wherein the user indicator unit includes a bi-color light emitting diode (LED), and the bi-color LED produces a first color when the calculated difference is greater than or equal to zero, and a second color when the calculated difference is less than zero.

11. A method of implanting a medical device at a desired implant depth within a human body, the method comprising: creating a pocket within the human body for the medical device; positioning the medical device within the pocket; and determining, using a depth finding medical device, the depth of the implantable medical device within the human body is within the desired implant depth, wherein the pocket remains open during the determining of the depth.

12. The method of claim 11, further comprising closing the pocket after determining the medical device is within the desired implant depth.

13. The method of claim 11, wherein the depth finding medical device further comprises: a depth sensing unit; a user indicator unit; and a control unit; wherein the control unit is coupled to the depth sensing unit, and the user indicator unit; wherein the control unit includes a memory and a processor, and the memory stores instructions that, when executed by the processor, causes the control unit to: measure a first depth of an implantable medical device with the depth sensing unit; produce an indication based on the first depth of the implantable medical device and a second depth; and output, on the user indicator unit, the indication.

14. The method of claim 13, wherein the depth finding medical device further comprises: calculate a difference between the first depth and the second depth; and produce an indication based on the difference that includes at least one of the first depth, the second depth, and the difference between the first depth and the second depth.

15. The method of claim 13, wherein the depth sensing unit includes an ultrasonic depth sensor.

16. The method of claim 13, wherein the depth sensing unit includes at least one of an infrared sensor and a magnetic sensor.

17. The method of claim 13, wherein the second depth is a desired implant depth of the implantable medical device.

18. The method of claim 14, wherein output the indication includes creating a sound with the user indicator unit.

19. The method of claim 18, wherein the sound is a first sound when the calculated difference is greater than or equal to zero, and the sound is a second sound when the calculated difference is less than zero.

20. The method of claim 14, wherein the user indicator unit includes a bi-color LED, and the bi-color LED produces a first color when the calculated difference is greater than or equal to zero, and a second color when the calculated difference is less than zero.

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