IMPLANTABLE MEDICAL DEVICE

An implantable medical device includes a power source configured to supply electrical impulses to a lead. A housing encloses the power source, and the housing includes a posterior surface, an anterior surface, and a circumferential edge extending between the posterior and anterior surfaces. The housing defines a storage area for excess slack of the lead.

BACKGROUND

Spinal cord stimulation is a medical therapy that is performed to alleviate chronic pain by stimulating the central nervous system. Typically, a distal end of a lead having electrical contacts is implanted in the epidural space of the spine, in close proximity to the spinal cord. A proximal end of the lead is connected to a stimulator, which includes a power source.

The stimulator is implanted into the buttock or lower back, and when activated, delivers electrical impulses to the electrical contacts on the distal end of the lead, for delivering the electrical impulses to the spinal cord or to a peripheral nerve. The electrical impulses activate pain inhibitory mechanisms to block the pain signal from reaching the brain, and thereby alleviate chronic pain such as for treating lower back pain.

SUMMARY

In general terms, the present disclosure relates to storage of excess slack of a lead connected to an implantable medical device. In one possible configuration, an implantable medical device has a housing with a storage area for the excess slack of the lead. In another possible configuration, an accessory attaches to an implantable medical device, and the accessory provides a storage area for the excess slack of the lead. Various aspects are described in this disclosure, which include, but are not limited to, the following aspects.

In one aspect, an implantable medical device is described. The implantable medical device comprises: a power source configured to supply electrical impulses to a lead; and a housing encloses the power source, the housing having: a posterior surface; an anterior surface; and a circumferential edge extending between the posterior and anterior surfaces; and wherein the housing defines a storage area for excess slack of the lead.

In another aspect, an accessory for an implantable medical device is described. The accessory comprises: a posterior surface having a convex shape; an anterior surface having a cavity configured to attach the accessory to a spinal cord stimulator device, and to partially encapsulate the spinal cord stimulator device; a circumferential edge extending between the posterior and anterior surfaces; and at least one storage area shaped for storing excess slack of a lead when the lead is connected to the spinal cord stimulator device.

DETAILED DESCRIPTION

The implantable medical device100includes a housing102having a posterior surface104, an anterior surface106, and a circumferential edge108extending between the posterior and anterior surfaces104,106. As used herein, “posterior” refers to the back of the human body and “anterior” refers to the front of the human body. Accordingly, the posterior surface104is directed toward the back of the body, while the anterior surface106is directed toward the front of the body when the implantable medical device100is implanted.

In a preferred embodiment, the implantable medical device100is a spinal cord stimulator device that has a power source110(seeFIG.42) programmed to generate electrical impulses for transmission through the one or more leads10. In some examples, the one or more leads10are percutaneous leads. In other examples, the one or more leads10are paddle leads. It is contemplated that in alternative embodiments, the implantable medical device100may be a different kind of medical device that is implantable into a body of a patient.

FIGS.3-8are anterior, posterior, right side, left side, top, and bottom views, respectively, of the implantable medical device100. As shown inFIGS.1-8, the posterior surface104, the anterior surface106, and the circumferential edge108of the housing102form an enclosure for the power source110. The housing102protects the power source110and other internal components from tissue and blood, as well as from impact with other objects when the implantable medical device100is implanted into a patient's body.

The housing102can be made of an inert and biocompatible material. For example, the housing102can be made of titanium or a titanium alloy, or similar materials.

Each lead of the one or more leads10extends from a proximal end to a distal end. Each lead has a standardized length. For example, the leads can have a standardized length of 50 cm or 70 cm. It is contemplated that the leads may have additional standardized lengths.

The figures illustrate an example in which four leads are connected to the implantable medical device100. In some examples, fewer than four leads are connected to the implantable medical device100such as one, two, or three leads can be connected. In some further examples, more than four leads can be connected to the implantable medical device100.

The figures further illustrate the housing102as having one or more openings124(seeFIG.5), which allow the leads10to enter housing102and attach to the power source110. In the example provided in the figures, the housing102includes four openings, which allows up to four leads to attach to the power source110. In alternative examples, the housing102can include more than four openings, or can include fewer than four openings. Also, while the one or more openings124are shown as positioned on the circumferential edge108, it is contemplated that the one or more openings124can be positioned elsewhere on the housing102.

The proximal end of each lead attaches to the implantable medical device100, and the distal end of each lead has electrical contacts that release electrical impulses to an area of the human body. In examples where the implantable medical device100is a spinal cord stimulator device, a distal end of a lead is implanted in the epidural space of the spine, such that the electrical contacts on the distal end can release the electrical impulses to the spinal cord or to a peripheral nerve to mitigate pain in the back, abdomen, chest, and other areas of the body.

The location where the distal end of a lead is implanted may vary along the epidural space in the spine depending on a treatment plan selected for mitigating pain in the back, abdomen, chest, and other areas of the body. For example, a distal end of a lead can be implanted between the T11 and T12 vertebrae, between the T12 and L1 vertebrae, above the T11 vertebrae, or below the L1 vertebrae. In certain examples, a distal end of a lead can be implanted at the T7 vertebrae, or can be implanted between the T9 and T10 vertebrae. These locations are provided by way of illustrative example, and it is contemplated that the distal ends of the leads can be implanted in additional areas in the epidural space of the spinal column. Additionally, the distal ends of different leads can be implanted in different areas of the epidural space. The location where a distal end of a lead is implanted is referred to herein as a first body area.

The implantable medical device100is implanted in a second body area. In some examples, the second body area is the buttock or lower back. In some further examples, the second body area can be an underarm, on the chest wall, or under the scalp.

When a distal end of a lead from the one or more leads10is implanted in the first body area (e.g., the epidural space in the spine) and the implantable medical device100is implanted in the second body area (e.g., the buttock or lower back), one or more of the leads10can have excess slack26(seeFIG.9). As an illustrative example, a lead can have excess slack when the standardized length of the lead (e.g., 50 cm or 70 cm) is longer than the distance between the first and second body areas. Accordingly, the excess slack of a lead can be defined as an excess amount of a first length over a second length, in which the first length is defined as a distance between the proximal and distal ends of the lead (e.g., the standardized length of the lead), and the second length is defined as a distance between the first and second body areas.

The implantable medical device100is configured to store the excess slack26of one or more of the leads10. Advantageously, storing the excess slack of the one or more leads10can reduce pain and discomfort that may be felt by a patient after the implantable medical device100and the one or more leads10have been implanted in the patient's body. Additionally, by storing the excess slack of the one or more leads10in a defined storage area can aid the removal or replacement of the one or more leads10of the implantable medical device100.

FIG.9is an isometric anterior view of the implantable medical device100with the excess slack26of the one or more leads10stored in the storage area. Referring now toFIGS.1-9, the housing102of the implantable medical device100is shaped to define a storage area for storing the excess slack26of the one or more leads10. In this example, the storage area is a negative space130shaped by the anterior surface106. For example, the anterior surface106has a concave shape that defines the negative space130. In alternative examples, the negative space130can be formed as a cutout or a hollowed portion on the anterior surface106.

In the example shown inFIGS.1-9, the posterior surface104is convex. The convex shape of the posterior surface104provides a contour generally conforming to the profile of the second body area where the implantable medical device100is implanted. Advantageously, this minimizes the appearance of the implantable medical device100when implanted under the skin of a patient, and provides an advantage over conventional spinal cord stimulators, which can create a noticeable bulge with defined edges that are visible, even under clothing.

The convex shape of the posterior surface104can vary depending on the desired location for implanting the implantable medical device100. For example, the convex shape of the posterior surface104can be varied to conform to the profile of a buttock, lower back, underarm, chest wall, scalp, and other suitable areas of the body for implanting the device.

As further shown inFIGS.1-9, the circumferential edge108is circular. Advantageously, the convex shape of the posterior surface104and the circular profile of the circumferential edge108can help to improve the distribution forces that are applied to the implantable medical device100when implanted, and thereby improve the durability of the device. For example, when the implantable medical device100is implanted into the buttock of a patient, and the patient sits down, the convex shape of the posterior surface104and the circular profile of the circumferential edge108can help to improve the distribution of the patient's weight applied to the implantable medical device100as a result of the patient sitting down. In the example shown in the figures, the convex shape of the posterior surface104and the circular profile of the circumferential edge108provide the housing102with a dome-shape.

The convex shape of the posterior surface104and the circular profile of the circumferential edge108can result in an increased surface area and overall size of the implantable medical device100over conventional spinal cord stimulators. This is an unexpected result because conventional spinal cord stimulators are designed to be as small as possible.

As shown inFIG.9, the excess slack26of the one or more leads10can be coiled for storage in the negative space130defined by the anterior surface106. The shape of the housing102can completely cover the excess slack26of the one or more leads10such that excess slack26is not exposed under the skin surface of the patient. This can help to mitigate irritation and discomfort that may result from loose leads, and can minimize the appearance of the excess slack26of the one or more leads10, which may bulge under the skin.

In some further examples, the excess slack26of the one or more leads10can be at least partially coiled around the circumferential edge108for storage. In such examples, the circular profile of the circumferential edge108can help facilitate coiling the excess slack26of the one or more leads10around the circumferential edge108. In some examples, the circumferential edge108can include a track, groove, or channel for coiling the excess slack26of the one or more leads10around the circumferential edge108.

FIGS.10and11are isometric posterior and interior views, respectively, of an implantable medical device200, in accordance with another embodiment of the present disclosure. As shown inFIGS.10and11, one or more leads10are connected to the implantable medical device200, which has a storage area for storing excess slack from the one or more leads10when the implantable medical device200and the one or more leads10are implanted.

FIGS.12-17are posterior, anterior, right side, left side, top, and bottom views, respectively, of the implantable medical device200. The implantable medical device200shares similar elements and features as the implantable medical device200described above with respect toFIG.1-9. For example, the implantable medical device200includes a housing202having a posterior surface204, an anterior surface206, and a circumferential edge208extending between the posterior and anterior surfaces204,206. The housing202can be made of an inert and biocompatible material such as titanium or a titanium alloy, or similar materials.

As shown inFIGS.10-17, the posterior surface204has a convex shape and the circumferential edge208has a circular profile. As described above, convex shape of the posterior surface204and the circular profile of the circumferential edge208can help to improve the distribution forces that are applied to the implantable medical device200when implanted, and thereby improve the durability of the implantable medical device200.

The convex shape of the posterior surface204and the circular profile of the circumferential edge208can result in an increased surface area and overall size of the implantable medical device200over conventional spinal cord stimulators. This is an unexpected result because conventional spinal cord stimulators are designed to be as small as possible.

The housing202of the implantable medical device200defines a storage area for storing the excess slack of the one or more leads10. In the example shown inFIGS.10-17, the storage area is a track230defined between the circumferential edge208and the posterior surface204that allows the one or more leads10to be at least partially looped around the housing202for storage to reduce the slack of the leads. In alternative examples, the track230can be defined around the circumferential edge208of the housing202.

In some examples, one or more of the leads10can be looped once, twice, or more around the housing202for storage to reduce the slack of the leads. In this example embodiment, another advantage of the circular profile of the circumferential edge208is that it facilitates wrapping, winding, or coiling the one or more leads10around the housing202for storage.

FIG.18a cross-sectional view of the implantable medical device200taken from the line18-18shown inFIG.12. As shown inFIG.18, the track230includes opposing edges232,234that can catch one or more of the leads10for containing one or more of the leads10inside the track230. In this example, the track230is channel or groove that is formed around the posterior surface204. Advantageously, the track230can mitigate irritation and discomfort that may result from loose leads, and can minimize the appearance of the excess slack26from the one or more leads10, which may bulge under the skin when left loose.

FIGS.19and20are isometric posterior and anterior views, respectively, of an implantable medical device300, in accordance with another embodiment of the present disclosure. The implantable medical device300has a storage area for storing the excess slack26from the one or more leads10when the implantable medical device and leads are implanted.

As shown inFIGS.19-22, the posterior surface304has a convex shape and the circumferential edge308has a circular profile. As described above, convex shape of the posterior surface304and the circular profile of the circumferential edge308can help to improve the distribution forces that are applied to the implantable medical device300when implanted, and thereby improve the durability of the implantable medical device300.

The convex shape of the posterior surface304and the circular profile of the circumferential edge308can result in the housing302having a dome-shape, which can increase surface area and overall size of the implantable medical device300over conventional spinal cord stimulators. As noted in the examples described above, this is an unexpected result because conventional spinal cord stimulators are designed to be as small as possible.

FIG.23is a cross-sectional view of the implantable medical device300taken from the line23-23shown inFIG.22. As shown inFIGS.22and23, the excess slack26of the one or more leads10can be stored in a storage area, which is a volume330defined inside the housing302of the implantable medical device300. Advantageously, the housing302can protect the excess slack26of the one or more leads10from tissue and blood, as well as from impact with other objects when the implantable medical device100is implanted.

In this example embodiment, the housing302includes a crank332for winding or coiling the excess slack26of the one or more leads10for storage inside the volume330of the housing302. The proximal ends of the one or more leads10can be attached or otherwise wrapped around a spool334. The crank332can be rotated by the fingers of a physician when implanting the implantable medical device300. The crank332can be rotated by a physician as necessary to adjust the excess slack26of the leads10outside of the volume330.

As shown inFIG.22, the crank332can be rotated in opposite directions to adjust the length of the one or more leads10outside of the volume330of the housing302. For example, the crank332can be rotated in a first direction D1(e.g., clockwise) to coil the one or more leads10around the spool334, and thereby reduce the excess slack26outside of the volume330. Also, the crank332can be rotated in a second direction D2(e.g., counterclockwise) to uncoil the one or more leads10, and thereby increase the excess slack26outside of the volume330

Advantageously, the crank332can be used to adjust the excess slack26of the leads10outside of the volume330of the housing302. Advantageously, this can mitigate irritation and discomfort that may result from loose leads under the patient's skin, and can minimize the appearance of the one or more leads10, which may bulge under the skin.

FIGS.24and25are isometric posterior and anterior views, respectively, of an accessory400for an implantable medical device. In a preferred embodiment, the accessory400is for a spinal cord stimulator device that has a power source110(seeFIG.42) programmed to generate electrical impulses for transmission through the one or more leads10, and the accessory400provides a storage area for the excess slack26of the one or more leads10.

FIGS.26-31are posterior, anterior, right side, left side, top, and bottom views, respectively, of the accessory400. As shown inFIGS.24-31, the accessory400includes a housing402having a posterior surface404, an anterior surface406, and a circumferential edge408extending between the posterior and anterior surfaces404,406.

The anterior surface406has a cavity410shaped and sized to receive an implantable medical device12(seeFIG.32). In some examples, the implantable medical device12is a conventional spinal cord stimulator device. The cavity410is structured to attach the accessory400to the implantable medical device12. When the accessory400is attached to the implantable medical device12, the accessory400partially encapsulates the implantable medical device12. For example, the accessory400can cover the posterior, left side, right side, top, and bottom surfaces of the implantable medical device12when it is held inside the cavity410.

In some examples, the housing402can be formed of a flexible material such that the housing402can flex around the implantable medical device12, and thereby hold and secure the implantable medical device12inside the cavity410. In some examples, the cavity410can include one or more snap fit fasteners412that are configured to attach the accessory400to the implantable medical device12. The housing402is made of a biocompatible and inert material, such as one or more polymers, including without limitation, silicon rubber, silicone elastomers, polyethylene, polyether ether ketone (PEEK), or any combinations thereof.

FIG.32is a cross-sectional view of the accessory400taken from the line32-32shown inFIG.27, and with an implantable medical device12inside the cavity410. As shown inFIGS.24-32, the housing402includes one or more bore holes414that can receive the leads10of the implantable medical device12. When the implantable medical device12is held inside the cavity410, one or more of the leads10can be threaded through the one or more bore holes414such that a proximal end of a lead can be attached to the implantable medical device12, and a distal end of the lead can be implanted in a body area such as the epidural space of the spine.

In the example illustrated inFIGS.24-32, the accessory400includes a bore hole414on opposite sides, thereby allowing one or more leads to attach to either side of the implantable medical device12. In other examples, the accessory400includes only one bore hole, or the accessory400can include more than two bore holes, as may be desirable.

In the example illustrated inFIGS.24-32, the posterior surface404of the accessory400has a convex shape. The convex shape of the posterior surface404provides a contour generally conforming to the profile of the second body area where the accessory400and implantable medical device12are implanted. Advantageously, this can minimize the appearance of the implantable medical device12when implanted under the skin of a patient, by mitigating the visual appearance of the defined edges of the implantable medical device.

The convex shape of the posterior surface404can vary depending on the desired location for implanting the implantable medical device12. For example, the convex shape of the posterior surface404can be varied to conform to the profile of a buttock, lower back, underarm, chest wall, scalp, and other suitable areas of the body.

As shown inFIGS.24-32, the circumferential edge408is circular. The convex shape of the posterior surface404and the circular profile of the circumferential edge408provide the housing402with a dome-shape. Advantageously, the dome-shape of the housing402can help to improve the distribution forces that are applied to the implantable medical device12when attached to the accessory400. For example, when the accessory400and implantable medical device12are implanted into the buttock of a patient, and the patient sits down, the dome-shape of the housing402can help to improve the distribution of the patient's weight applied to the implantable medical device12as a result of the patient sitting down.

The convex shape of the posterior surface404and the circular profile of the circumferential edge408are larger than the surface area and overall size of the implantable medical device12. This is an unexpected result because implantable medical devices, such as conventional spinal cord stimulators, are designed to be as small as possible.

Referring now toFIG.32, the accessory400is shaped and sized to store the excess slack26of one or more of the leads10when attached to the implantable medical device12. Advantageously, storing the excess slack26of the one or more leads10can reduce pain and discomfort that may be felt by a patient from the implantable medical device12and the one or more leads10having been implanted into the patient's body. Additionally, the accessory400provides a defined storage area for storing the excess slack of the one or more leads10, which can aid in the removal or replacement of the one or more leads10.

As shown inFIG.32, the housing402is shaped to define the storage area for storing the excess slack of the one or more leads10as a negative space430formed by the anterior surface406of the accessory400. The anterior surface406surrounds the implantable medical device12, and the anterior surface406has a concave shape that partially defines the negative space430for storing the excess slack26from the one or more leads10. Thus, the accessory400can store the excess slack26of one or more of the leads10in a similar fashion as the embodiment of the implantable medical device100shown inFIGS.1-9.

As shown inFIG.32, the negative space430for storing the excess slack is bounded by the anterior surface406of the accessory400and by an anterior surface14of the implantable medical device12. In the example shown inFIG.32, the implantable medical device12has an anterior surface14that is substantially flat. In alternative examples, the negative space430can be formed as a cutout or a hollowed portion on the anterior surface406of the accessory400.

In some further examples, the excess slack26of the one or more leads10can be at least partially coiled around the circumferential edge408of the accessory400for storage. In such examples, the circular profile of the circumferential edge408can help facilitate coiling the excess slack26of the one or more leads10around the circumferential edge408. In some examples, the circumferential edge408can include a track, groove, or channel for coiling the excess slack26of the one or more leads10around the circumferential edge408.

FIGS.33-41are isometric posterior, isometric anterior, posterior, anterior, right side, left side, top, bottom, and cross-sectional views, respectively, of an accessory500in accordance with another embodiment of the present disclosure. The accessory500is shaped and sized to provide a storage area for excess lead slack from an implantable medical device. In a preferred embodiment, the accessory500is designed for a conventional spinal cord stimulator device.

The accessory500shares similar elements and features with the accessory400described above with respect toFIG.24-32. For example, the accessory500includes a housing502having a posterior surface504, an anterior surface506, and a circumferential edge508extending between the posterior and anterior surfaces504,506. The anterior surface506has a cavity510shaped and sized to receive an implantable medical device12(seeFIG.41). In some examples, the implantable medical device12is a conventional spinal cord stimulator device.

The cavity510is structured to attach the accessory500to the implantable medical device12. When the accessory500is attached to the implantable medical device12, the accessory500partially encapsulates the implantable medical device12. For example, as shown inFIG.41, the accessory500covers the posterior, left side, right side, top, and bottom surfaces of the implantable medical device12when it is held inside the cavity510.

In some examples, the housing502can be formed of a flexible material such that the housing502can flex around the implantable medical device12, and thereby hold and secure the implantable medical device12inside the cavity510. In some examples, the cavity510can include one or more snap fit fasteners512that are configured to attach the accessory500to the implantable medical device12. The housing502is made of a biocompatible and inert material, such as one or more polymers, including without limitation, silicon rubber, silicone elastomers, polyethylene, polyether ether ketone (PEEK), or any combinations thereof.

The housing502includes one or more bore holes514that can receive one or more of the leads10that attach to the implantable medical device12. The one or more bore holes514are similar as the bore holes414described above with reference to accessory400.

In the example illustrated inFIGS.33-41, the posterior surface504of the accessory500has a convex shape. The convex shape of the posterior surface504provides a contour generally conforming to the profile of a location of the body where it is desirable to implant the implantable medical device12. Advantageously, the convex shape of the posterior surface504can minimize the appearance of the implantable medical device12when implanted under the skin by mitigating the visual appearance of the defined edges of the implantable medical device.

The convex shape of the posterior surface504can vary depending on the desired location for implanting the implantable medical device12. For example, the convex shape of the posterior surface504can be varied to conform the shape of the accessory500to the profile of a buttock, lower back, underarm, chest wall, scalp, and other suitable areas of the body.

In the example illustrated inFIGS.33-41, the circumferential edge508is circular. The convex shape of the posterior surface504and the circular profile of the circumferential edge508provide the housing502with a dome-shape that can help to improve the distribution forces applied to the implantable medical device12when attached to the accessory500. For example, when the implantable medical device12is implanted into the buttock of a patient, and the patient sits down, the dome-shape of the housing502can improve the distribution of the patient's weight applied to the implantable medical device12as a result of the patient sitting down.

The convex shape of the posterior surface504and the circular profile of the circumferential edge508are larger than the surface area and overall size of the implantable medical device12. This is an unexpected result because implantable medical devices, such as conventional spinal cord stimulators, are designed to be as small as possible.

The housing502defines a storage area for storing the excess slack26of the one or more leads10. In the example shown inFIGS.33-41, the storage area is a track530on the posterior surface504that allows the one or more leads10to be at least partially looped around the housing502to reduce the excess slack26of the leads. In some examples, one or more of the leads10can be looped once, twice, or more around the track530for storage. In this example embodiment, another advantage of the circular profile of the circumferential edge508is that it facilitates wrapping, winding, or coiling the one or more leads10around the track530.

As shown inFIG.41, which is a cross-sectional view of the accessory500taken from the line41-41shown inFIG.35, and which shows the implantable medical device12inside the cavity510, the track530includes opposing edges532,534that can catch one or more of the leads10for containing the leads inside the track530. Thus, the accessory500can store the excess slack26of one or more of the leads10in a similar fashion as the embodiment of the implantable medical device200shown inFIGS.10-18. Advantageously, the track530can mitigate irritation and discomfort from loose leads, and can minimize the appearance of the excess slack26of the one or more leads10, which may bulge under the skin.

FIG.42schematically illustrates components of the implantable medical device100,200,300in accordance with the embodiments described above. As shown inFIG.42, the implantable medical device100,200,300includes at least one processing unit112that regulates the operation of the power source110to generate the electrical impulses.

The implantable medical device100,200,300includes a system memory114. The system memory114may include volatile storage (e.g., random access memory), non-volatile storage (e.g., read-only memory), flash memory, or any combinations thereof. The system memory114may include an operating system and program modules for running software applications performed by the at least one processing unit112to control the operation of the power source110and other components of the implantable medical device.

The implantable medical device100,200,300further includes a communications unit116for receiving commands from an external remote control118. The external remote control118allows a patient to adjust the stimulation provided by the implantable medical device100,200,300such as by regulating the electrical impulses that are generated by the power source110and that are released by the electrical contacts of the one or more leads10.

The implantable medical device100,200,300includes one or more lead connectors120that can receive the proximal ends of the one or more leads10. As an illustrative example, the implantable medical device100,200,300can include one, two, three, four, or more lead connectors120for connecting one, two, three, four, or more leads to the power source110.

The implantable medical device100,200,300includes an electrical circuit122that connects the various components illustrated inFIG.42including the power source110, the at least one processing unit112, the system memory114, the communications unit116, and the lead connectors120. The electrical circuit122can be a circuit having discrete electronic elements, packaged or integrated electronic chips containing logic gates, or a single chip containing electronic elements. The electrical circuit122can be a system-on-a-chip (SOC) on which the components illustrated inFIG.42are integrated. When operating via an SOC, the functionality of the implantable medical device100,200,300may be operated via application-specific logic integrated with other components on a single integrated circuit.

The various embodiments described above are provided by way of illustration only and should not be construed to be limiting in any way. Various modifications can be made to the embodiments described above without departing from the true spirit and scope of the disclosure.