Electrical contacts for medical devices

Abstract

A electrical contact for coupling a contact of a medical lead with electronics of a medical device is described. For example, the electrical contact includes an outer wall defining a contact longitudinal axis and including an inner surface and an outer surface. The electrical contact can include a plurality of deflectable fingers extending radially inward from the outer wall and into a contact opening defined by the inner surface of the outer wall, wherein the outer wall comprises a plurality of protrusions, each respective protrusion of the plurality of protrusions is configured to prevent the medical lead from moving a respective deflectable finger of the plurality of deflectable fingers beyond a radial limit defined by the respective protrusion. The electrical contact can be configured to be disposed within a housing defining a housing longitudinal axis such that the contact longitudinal axis is aligned with the housing longitudinal axis.

Description

ELECTRICAL CONTACTS FOR MEDICAL DEVICESCROSS-RELATED APPLICATION

[0001] This application claims the benefit of priority to U.S. Provisional Application No. 63 / 665,762, filed June 28, 2024, which is incorporated herein by reference in its entirety.TECHNICAL FIELD

[0002] This disclosure generally relates to medical devices, and more specifically, an electrical contact for a medical device.BACKGROUND

[0003] Electrical stimulation devices, sometimes referred to as neurostimulators or neurostimulation devices, may be external to or implanted within a patient, and configured to deliver electrical stimulation therapy to various tissue sites to treat a variety of symptoms or conditions such as chronic pain, tremor, Parkinson’s disease, epilepsy, or other neurological disorders, urinary or fecal incontinence, sexual dysfunction, obesity, or gastroparesis. An electrical stimulation device may deliver electrical stimulation therapy via electrodes, e.g., carried by one or more leads. The one or more leads may be electrically coupled with an implantable medical device via a connector within the medical device.SUMMARY

[0004] This disclosure is directed to an electrical contact for medical devices that may be configured to deliver electrical stimulation therapy. An electrical stimulation device may deliver electrical stimulation therapy via electrodes, e.g., carried by one or more leads. The one or more leads may be electrically coupled with an implantable medical device via an electrical contact within the medical device. The electrical contact may include one or more deflectable fingers configured to form an electrical connection with a contact of the lead.

[0005] The deflectable fingers may be V-shaped, spoon shaped, or have any other shapes configured to facilitate contact with an inserted lead. Each deflectable finger may include an “s” shaped proximal region that prevents the base of the deflectable finger from moving radiallyoutward and contacting a housing holding the electrical contact when the medical lead is inserted. The electrical contact may include one or more protrusions on the outer wall that prevent a respective deflectable finger from moving beyond a radial limit when the lead is inserted into the opening defined by the outer wall of the electrical contact.

[0006] In one or more examples, an electrical contact for coupling a contact of a medical lead with electronics of a medical device includes: an outer wall defining a contact longitudinal axis and comprising an inner surface and an outer surface, wherein the inner surface defines a contact opening; a plurality of deflectable fingers extending radially inward from the outer wall and into the contact opening defined by the inner surface of the outer wall, wherein: the outer wall comprises a plurality of protrusions, each respective protrusion of the plurality of protrusions is configured to prevent the medical lead from moving a respective deflectable finger of the plurality of deflectable fingers beyond a radial limit defined by the respective protrusion; and the electrical contact is configured to be disposed within a housing defining a housing longitudinal axis such that the contact longitudinal axis is aligned with the housing longitudinal axis.

[0007] In one or more examples, an implantable medical device configured to deliver electrical stimulation therapy, the medical device including: an electronics housing having a connector header; an electrical contact disposed within the connector header, the electrical contact configured for coupling a medical lead with electronics of the medical device configured to deliver electrical stimulation therapy, the electrical contact comprising: an outer wall defining a contact longitudinal axis and comprising an inner surface and an outer surface, wherein the inner surface defines a contact opening; and a plurality of deflectable fingers extending radially inward from the outer wall and into the contact opening defined by the inner surface of the outer wall, wherein the outer wall comprises a plurality of protrusions, and wherein each respective protrusion of the plurality of protrusions is configured to prevent the medical lead from moving a respective deflectable finger of the plurality of deflectable fingers beyond a radial limit defined by the respective protrusion; and a housing defining an opening therein, the opening configured to receive the electrical contact therein, wherein the housing is defined in part by a housing longitudinal axis and a housing inner diameter, and wherein the electrical contact is configured to be disposed within the housing such that the contact longitudinal axis is aligned with the housing longitudinal axis.

[0008] In one or more examples, a method for forming an electrical contact includes: stamping an electrical contact from a strip of material; forming a plurality of deflectable fingers from the strip of material; forming a plurality of protrusions from the strip of material; forming the stamped contact member into a ring shaped wall defining a longitudinal axis and comprising an inner surface and an outer surface, the inner surface defining a contact opening, wherein: the plurality of deflectable fingers extend radially inward from the outer wall and into the contact opening defined by the inner surface of the outer wall; the outer wall comprises the plurality of protrusions, wherein each respective protrusion of the plurality of protrusions is configured to prevent a medical lead from moving a respective deflectable finger of the plurality of deflectable fingers beyond a radial limit defined by the respective protrusion; and the electrical contact is configured to be disposed within a housing defining a housing longitudinal axis such that the contact longitudinal axis is aligned with the housing longitudinal axis

[0009] The summary is intended to provide an overview of the subject matter described in this disclosure. It is not intended to provide an exclusive or exhaustive explanation of the systems, device, and methods described in detail within the accompanying drawings and description below. Further details of one or more examples of this disclosure are set forth in the accompanying drawings and in the description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims.BRIEF DESCRIPTION OF DRAWINGS

[0010] FIG. 1 is a conceptual diagram illustrating an example system that includes an implantable medical device (IMD) in the form of a neurostimulation device configured to deliver spinal cord stimulation (SCS), an external programmer in accordance with one or more techniques of this disclosure.

[0011] FIG. 2A is a side view illustrating an example system that includes an implantable medical device (IMD) in accordance with one or more techniques of this disclosure.

[0012] FIG. 2B is a side view illustrating an example system that includes an implantable medical device (IMD) in accordance with one or more techniques of this disclosure.

[0013] FIG. 2C is an enlarged view illustrating a portion of a header and a portion of a lead in accordance with one or more techniques of this disclosure.

[0014] FIG. 3A is a perspective view illustrating an electrical contact for an implantable medical device (IMD) in accordance with one or more techniques of this disclosure.

[0015] FIG. 3B is an end view illustrating an electrical contact for an implantable medical device (IMD) in accordance with one or more techniques of this disclosure.

[0016] FIG. 3C is a cross-sectional side view illustrating an electrical contact for an implantable medical device (IMD) in accordance with one or more techniques of this disclosure.

[0017] FIG. 3D is a conceptual diagram illustrating a housing for an electrical contact for an implantable medical device (IMD) in accordance with one or more techniques of this disclosure.

[0018] FIG. 3E is a cross-sectional side view illustrating a housing for an electrical contact for an implantable medical device (IMD) in accordance with one or more techniques of this disclosure.

[0019] FIG. 4A is a first end view illustrating an electrical contact in accordance with one or more techniques of this disclosure.

[0020] FIG. 4B is a side view illustrating an electrical contact in accordance with one or more techniques of this disclosure.

[0021] FIG. 4C is a close up view of a protrusion of an electrical contact.

[0022] FIG. 4D is a perspective view illustrating a contact member for an electrical contact in accordance with one or more techniques of this disclosure.

[0023] FIGS. 4E and 4F are close up side views of example protrusions for an electrical contact.

[0024] FIG. 5A is a top view of a stamped contact member for an electrical contact in accordance with one or more techniques of this disclosure.

[0025] FIG. 5B is a side view of the stamped contact member of FIG. 5 A.

[0026] FIG. 6 is a flow diagram illustrating assembly of an electrical contact in accordance with one or more techniques of this disclosure.DETAILED DESCRIPTION

[0027] Electrical stimulation devices, sometimes referred to as neurostimulators or neurostimulation devices, may be external to or implanted within a patient, and configured to deliver electrical stimulation therapy to various tissue sites to treat a variety of symptoms or conditions such as chronic pain, tremor, Parkinson’s disease, epilepsy, or other neurologicaldisorders, urinary or fecal incontinence, sexual dysfunction, obesity, or gastroparesis. An electrical stimulation device may deliver electrical stimulation therapy via electrodes, e.g., carried by one or more leads. The one or more leads may be electrically coupled with an implantable medical device via an electrical contact within the medical device.

[0028] An electrical contact provides an electrical interface between the lead and the implantable medical device. The electrical contact may accommodate varying sizes or diameters of the leads. The electrical contact may also provide a lower insertion force to facilitate assembly of the lead with the implantable medical device, and yet a higher contact force to facilitate electrical connection between the lead and the implantable medical device. The electrical contact may be used in a terminal (e.g., a housing) of an implantable medical device which receives the lead therein. This disclosure describes electrical contacts and techniques for fabricating electrical contacts for use with medical devices.

[0029] In some examples, the electrical contact may include one or more deflectable fingers that are configured to deflect radially outward in response to a lead being inserted within the electrical contact such that the distal end of the deflectable finger provides a bias force against a contact of the medical lead. In some examples, multiple deflectable fingers are positioned around the circumference of the electrical contact and configured to establish electrical connections to respective contacts on the medical lead.

[0030] Each deflectable finger may include a base portion that extends from the electrical contact. This base portion may include an “s” shaped portion that includes a radially inward curvature followed by a radially outward curvature. This “s” shaped portion may reduce the likelihood that the base portion of the deflectable finger contacts the housing upon being pushed outward by the medical lead. Such contact with the housing can effectively reduce the length of the deflectable member and increase the stress and strain on the deflectable finger which could lead to fracture and / or plastic deformation of the deflectable finger.

[0031] The electrical contact may also include protrusions on the outer wall of the electrical contact, where each protrusion is configured to prevent the medical lead from moving a respective deflectable finger beyond a radial limit defined by that protrusion. In other words, the protrusion may act as a “stop” or distance limit by contacting the medical lead and preventing the medical lead from moving the deflectable finger further radially from the longitudinal axis of the electrical contact. In some examples, each protrusion may have two or more portions that definea center channel that is configured to accept the distal portion of the deflectable finger when forced radially outward by the medical lead. The protrusions may reduce or prevent any plastic deformation (and reduced bias force) that could occur with the deflectable finger during insertion of the medical lead.

[0032] An electrical stimulation system may include a stimulator system that interacts with a stimulator programmer. FIG. 1 is a conceptual diagram illustrating an example system 100 that includes an implantable medical device (IMD) 110 configured to deliver spinal cord stimulation (SCS) therapy, processing circuitry 140, and an external programmer 150, in accordance with one or more examples of this disclosure. Although the examples described in this disclosure are generally applicable to a variety of medical devices including external devices and IMDs, application of such techniques to IMDs and, more particularly, implantable electrical stimulators (e.g., neurostimulators) will be described for purposes of illustration. More particularly, the disclosure will refer to an implantable SCS system for purposes of illustration, but without limitation as to other types of neurostimulation devices or other therapeutic applications of neurostimulation. The electrical contact and related features described herein can be used in other medical or non-medical applications as well to provide electrical contacts between two or more components.

[0033] As shown in FIG. 1, system 100 includes an IMD 110, leads 130A and 130B, and external programmer 150 shown in conjunction with a patient 105, who is ordinarily a human patient. In the example of FIG. 1, IMD 110 is an implantable electrical stimulator that is configured to generate and deliver electrical stimulation therapy to patient 105, e.g., for relief of chronic pain or other symptoms, via one or more electrodes 132A, 132B of leads 130A and / or 130B, respectively. In the example of FIG. 1, each lead 130A, 130B includes eight electrodes 132A, 132B respectively, although the leads may each have a different number of electrodes. Leads 130A, 130B may be referred to collectively as “leads 130” and electrodes 132A, 132B may be referred to collectively as electrodes 132. In other examples, IMD 110 may be coupled to a single lead carrying multiple electrodes or more than two leads each carrying multiple electrodes.

[0034] IMD 110 may be a chronic electrical stimulator that remains implanted within patient 105 for weeks, months, or years. In other examples, IMD 110 may be a temporary, or trial, stimulator used to screen or evaluate the efficacy of electrical stimulation for chronic therapy. Inone example, IMD 110 is implanted within patient 105, while in another example, IMD 110 is an external device coupled to one or more leads percutaneously implanted within the patient. In some examples, IMD 110 uses electrodes on one or more leads, while in other examples, IMD 110 use one or more electrodes on a lead or leads and one of more electrodes on a housing of the IMD.

[0035] IMD 110 may be constructed of any polymer, metal, or composite material sufficient to house the components of IMD 110 (e.g., components illustrated in FIG. 2A, 2B) within patient 105. In this example, IMD 110 may be constructed with a biocompatible housing, such as titanium or stainless steel, or a polymeric material such as silicone, polyurethane, or a liquid crystal polymer, and surgically implanted at a site in patient 105 near the pelvis, abdomen, or buttocks. In other examples, IMD 110 may be implanted at other suitable sites within patient 105, which may depend, for example, on the target site within patient 105 for the delivery of electrical stimulation therapy. The outer housing of IMD 110 may be configured to provide a hermetic seal for components, such as a rechargeable or non-rechargeable power source. In addition, in some examples, the outer housing of IMD 110 is selected from a material that facilitates receiving energy to charge the rechargeable power source.

[0036] In the example of FIG. 1, electrical stimulation energy, which may be delivered as regulated current or regulated voltage- based pulses, is delivered from IMD 110 to one or more target tissue sites of patient 105 via leads 130 and electrodes 132. Leads 130 position electrodes 132 adjacent to target tissue of spinal cord 120. One or more of the electrodes 132 may be disposed at a distal tip of a lead 130 and / or at other positions at intermediate points along the lead. Leads 130 may be implanted and coupled to IMD 110. The electrodes 132 may transfer electrical stimulation generated by an electrical stimulation generator in IMD 110 to tissue of patient 105. Although leads 130 may each be a single lead, a lead 130 may include a lead extension or other segments that may aid in implantation or positioning of lead 130.

[0037] The electrodes 132 of leads 130 may be electrode pads on a paddle lead, circular (e.g., ring) electrodes surrounding the body of the lead, conformable electrodes, cuff electrodes, segmented electrodes (e.g., electrodes disposed at different circumferential positions around the lead instead of a continuous ring electrode), any combination thereof (e.g., ring electrodes and segmented electrodes) or any other type of electrodes capable of forming unipolar, bipolar or multipolar electrode combinations for therapy. Ring electrodes arranged at different axialpositions at the distal ends of lead 130 will be described for purposes of illustration. Deployment of electrodes via leads 130 is described for purposes of illustration, but electrodes may be arranged on a housing of IMD 110, e.g., in rows and / or columns (or other arrays or patterns), as surface electrodes, ring electrodes, or protrusions.

[0038] Neurostimulation parameters defining the electrical stimulation pulses delivered by IMD 110 through electrodes 132 of leads 130 may include information identifying which electrodes have been selected for delivery of the stimulation pulses according to a stimulation program and the polarities of the selected electrodes (the electrode combination), and voltage or current amplitude, pulse rate (i.e., frequency), and pulse width of the stimulation pulses. The neurostimulation parameters may further include a cycle parameter that specifies when, or how long, stimulation is turned on and off. Neurostimulation stimulation parameters may be programmed prior to delivery of the neurostimulation pulses, manually adjusted based on user input, or automatically controlled during delivery of the neurostimulation pulses, e.g., based on sensed conditions.

[0039] Although the example of FIG. 1 is directed to SCS therapy, e.g., to treat pain, in other examples, system 100 may be configured to treat other conditions that may benefit from neurostimulation therapy. For example, system 100 may be used to treat tremor, Parkinson’s disease, epilepsy, or other neurological disorders, urinary or fecal incontinence, sexual dysfunction, obesity, or gastroparesis, or psychiatric disorders such as depression, mania, obsessive compulsive disorder, anxiety disorders, or cardiac disorders. Hence, in some examples, system 100 may be configured to deliver sacral neuromodulation (SNM), deep brain stimulation (DBS), peripheral nerve stimulation (PNS), or other stimulation, such as peripheral nerve field stimulation (PNFS), cortical stimulation (CS), gastrointestinal stimulation, or any other stimulation therapy capable of treating a condition of patient 105. In some examples, system 100 may be configured where the electrical stimulation includes parameters to deliver therapy to address a condition of one or more of painful diabetic neuropathy (PDN), peripheral vascular disease (PVD), peripheral artery disease (PAD), complex regional pain syndrome (CRPS), leg pain, back pain or pelvic pain.

[0040] Leads 130 may include, in some examples, one or more sensors configured to sense one or more physiological parameters of patient 105, such as patient activity, pressure, temperature, posture, heart rate, or other characteristics. At least some of electrodes 132 may beused to sense electrical signals within patient 105, additionally or alternatively to delivering stimulation. IMD 110 is configured to deliver electrical stimulation therapy to patient 105 via selected combinations of electrodes carried by one or both of leads 130, alone or in combination with an electrode carried by or defined by an outer housing of IMD 110. The target tissue for the electrical stimulation therapy may be any tissue affected by electrical stimulation. In some examples, the target tissue includes nerves, smooth muscle or skeletal muscle. In the example illustrated by FIG. 1, the target tissue is tissue proximate spinal cord 120, such as within an intrathecal space or epidural space of spinal cord 120, or, in some examples, adjacent nerves that branch off spinal cord 120. Leads 130 may be introduced into spinal cord 120 in via any suitable region, such as the thoracic, cervical or lumbar regions.

[0041] Stimulation of spinal cord 120 may, for example, prevent pain signals from traveling through spinal cord 120 and to the brain of patient 105. Patient 105 may perceive the interruption of pain signals as a reduction in pain and, therefore, efficacious therapy results. In other examples, stimulation of spinal cord 120 may produce paresthesia which may reduce the perception of pain by patient 105, and thus, provide efficacious therapy results. In some examples, some electrical stimulation pulses may be directed to glial cells while other electrical stimulation (e.g., delivered by a different electrode combination) is directed to neurons.

[0042] IMD 110 generates and delivers electrical stimulation therapy to a target stimulation site within patient 105 via the electrodes of leads 130 to patient 105 according to one or more therapy stimulation programs. A therapy stimulation program specifies values for one or more parameters that define an aspect of the therapy delivered by IMD 110 according to that program. For example, a therapy stimulation program that controls delivery of stimulation by IMD 110 in the form of stimulation pulses may define values for voltage or current pulse amplitude, pulse width, and pulse rate (e.g., pulse frequency) for stimulation pulses delivered by IMD 110 according to that program, as well as the particular electrodes and polarities forming an electrode combination used to deliver the stimulation pulses.

[0043] A user, such as a clinician or patient 105, may interact with a user interface of an external programmer 150 to program IMD 110. Programming of IMD 110 may refer generally to the generation and transfer of commands, programs, or other information to control the operation of IMD 110. In this manner, IMD 110 may receive the transferred commands and programs from external programmer 150 to control electrical stimulation therapy. For example,external programmer 150 may transmit therapy stimulation programs, stimulation parameter adjustments, therapy stimulation program selections, user input, or other information to control the operation of IMD 110, e.g., by wireless telemetry or wired connection.

[0044] In some cases, external programmer 150 may be characterized as a physician or clinician programmer if it is primarily intended for use by a physician or clinician. In other cases, external programmer 150 may be characterized as a patient programmer if it is primarily intended for use by a patient. A patient programmer may be generally accessible to patient 105 and, in many cases, may be a portable device that may accompany patient 105 throughout the patient’s daily routine. For example, a patient programmer may receive input from patient 105 when the patient wishes to terminate or change stimulation therapy. In general, a physician or clinician programmer may support selection and generation of programs by a clinician for use by IMD 110, whereas a patient programmer may support adjustment and selection of such programs by a patient during ordinary use. In other examples, external programmer 150 may include, or be part of, an external charging device that recharges a power source of IMD 110. In this manner, a user may program and charge IMD 110 using one device, or multiple devices.

[0045] IMD 110 and external programmer 150 may exchange information and may communicate via wireless communication using any techniques known in the art. Examples of communication techniques may include, for example, radiofrequency (RF) telemetry and inductive coupling, but other techniques are also contemplated. In some examples, external programmer 150 includes a communication head that may be placed proximate to the patient’s body near the IMD 110 implant site to improve the quality or security of communication between IMD 110 and external programmer 150. Communication between external programmer 150 and IMD 110 may occur during power transmission or separate from power transmission.

[0046] IMD 110, in response to commands from external programmer 150, may deliver electrical stimulation therapy according to a plurality of therapy stimulation programs to a target tissue site of a patient via of the spinal cord 120 of patient 105 via electrodes on leads 130. In some examples, IMD 110 automatically modifies therapy stimulation programs as therapy needs of patient 105 evolve over time. For example, the modification of the therapy stimulation programs may cause the adjustment of at least one parameter of the plurality of stimulation pulses based on received information.

[0047] FIG. 2A shows an IMD 210, which may be an implantable electrical stimulator that is configured to generate and deliver electrical stimulation therapy to patient for relief of symptoms via one or more electrodes 236. IMD 210 may be a chronic electrical stimulator that remains implanted within a patient for weeks, months, or years. In other examples, IMD 210 may be a temporary, or trial, stimulator used to screen or evaluate the efficacy of electrical stimulation for chronic therapy. In one example, IMD 210 is implanted within a patient, while in another example, IMD 210 is an external device coupled to one or more leads percutaneously implanted within the patient. In some examples, IMD 210 uses electrodes on one or more leads, while in other examples, IMD 210 use one or more electrodes on a lead or leads and one of more electrodes on a housing of the IMD.

[0048] IMD 210 may include an electronics housing 226 having a connector header 220. One or more connector channels 290 may be disposed within the connector header 220. Each connector channel may include one or more electrical contact system 250 and, typically, a plurality of electrical contact systems. Electrical contact system 250 may include an electrical contact (or contact member) and, in some examples, a housing into which the electrical contact is disposed. The electrical contact system 250 may be configured for coupling an extension 228 with electronics of IMD 210 configured to deliver electrical stimulation therapy. A distal end 235 of extension 228 may be electrically coupled with a proximal end 232A of lead 230A to electrically connect the IMD 210 with the lead 230A. The electronics housing 226 and / or header 220 may be constructed of any polymer, metal, or composite material sufficient to house the components of IMD 210. In this example, IMD 210 may be constructed with a biocompatible housing, such as titanium or stainless steel, or a polymeric material such as silicone, polyurethane, or a liquid crystal polymer, and surgically implanted at a site in a patient near the pelvis, abdomen, or buttocks. In other examples, IMD 210 may be implanted at other suitable sites within a patient, which may depend, for example, on the target site within the patient 105 the delivery of electrical stimulation therapy. The outer housing of IMD 210 may be configured to provide a hermetic seal for components, such as a rechargeable or non-rechargeable power source. In addition, in some examples, the outer housing of IMD 210 is selected from a material that facilitates receiving energy to charge the rechargeable power source.

[0049] IMD 210 may provide therapy to one or more target tissue sites of the patient via lead 230 A and electrodes 236. Lead 230A may extend from a proximal end 232A to a distal end234A. One or more of the electrodes 236 may be disposed at a distal end 234A of the lead 230A and / or at other positions at intermediate points along the lead. One or more proximal lead contact systems 240A may be disposed at the proximal end 232A of the lead 230A. Lead 230A may be implanted and coupled to distal end 235 of extension 228. Proximal end 229 of the extension 228 may be coupled with IMD 210 at the proximal end 232 of the lead 230, and proximal contacts 241 may electrically couple with respective electrical contact systems within a connector channel 250 within the connector header 220.

[0050] FIG. 2B shows an IMD 210 which may be an implantable electrical stimulator that is configured to generate and deliver electrical stimulation therapy to patient for relief of symptoms, via one or more electrodes 236. IMD 210 may be a chronic electrical stimulator that remains implanted within a patient for weeks, months, or years. In other examples, IMD 210 may be a temporary, or trial, stimulator used to screen or evaluate the efficacy of electrical stimulation for chronic therapy. In one example, IMD 210 is implanted within a patient, while in another example, IMD 210 is an external device coupled to one or more leads percutaneously implanted within the patient. In some examples, IMD 210 uses electrodes on one or more leads, while in other examples, IMD 210 use one or more electrodes on a lead or leads and one of more electrodes on a housing of the IMD.

[0051] IMD 210 may include an electronics housing 226 having a connector header 220. One or more connector channels 290 may be disposed within the connector header 220. Each connector channel may include one or more electrical contact systems and, typically, a plurality of electrical contact systems. An electrical contact system 250 may be configured for coupling medical leads 230B with electronics of IMD 210 configured to deliver electrical stimulation therapy, where FIG. 2B shows two medical leads. The housing 226 and / or header 220 may be constructed of any polymer, metal, or composite material sufficient to house the components of IMD 210. In this example, IMD 210 may be constructed with a biocompatible housing, such as titanium or stainless steel, or a polymeric material such as silicone, polyurethane, or a liquid crystal polymer, and surgically implanted at a site in a patient near the pelvis, abdomen, or buttocks. In other examples, IMD 210 may be implanted at other suitable sites within a patient, which may depend, for example, on the target site within the patient 105 the delivery of electrical stimulation therapy. The outer housing of IMD 210 may be configured to provide a hermetic seal for components, such as a rechargeable or non-rechargeable power source. In addition, insome examples, the outer housing of IMD 210 is selected from a material that facilitates receiving energy to charge the rechargeable power source.

[0052] IMD 210 may provide therapy to one or more target tissue sites of the patient via leads 230B and electrodes 236. Lead 230 may extend from a proximal end 232B to a distal end 234B. One or more of the electrodes 236 may be disposed at a distal end 234B of the lead 230B and / or at other positions at intermediate points along the lead. One or more proximal lead contacts 240B may be disposed at the proximal end 232B of the leads 230B. Leads 230B may be implanted and coupled to IMD 210 at the proximal end 232B of the leads 230B, and proximal contacts 240B may electrically couple with respective electrical contact systems within a connector channel 250 within the connector header 220.

[0053] FIG. 2C shows a connector channel 290 of connector header 220 with four electrical contact systems 250A, 250B, 250C, 250D disposed within the header 220. The four electrical contact systems 250A, 250B, 250C, 250D may be disposed in a row in the connector channel 290 so as to be positioned to receive a proximal end 232 of a lead 230C and align with four respective proximal lead contacts 240A, 240B, 240C, 240D of the lead 230C to electrically connect them to respective circuitry terminals. In some examples, each electrical contact system 250 may include one, two, three, four, or more fingers configured to extend radially inward from an inner surface of the contact. In this manner, although three deflectable fingers are described in some examples herein, similar electrical contacts may be constructed to have as few as one or four or more deflectable fingers in other examples. The finger may be spoon-shaped, as shown in the example of FIG. 2C. A spoon shaped finger may include a rounded end and a neck proximal from the rounded end, wherein the neck is narrower than the rounded end, and wherein the rounded end comprises a curved surface. This neck and rounded end with a curved surface may be referred to as a spoon shaped finger. In other examples, the deflectable finger may have other shapes such as a V-shaped finger that has a narrowing width moving towards the distal end. In other examples, the finger may have different widths along the length of the finger.

[0054] As shown in FIG. 2A - 2C, the proximal end of the lead or lead extension may be inserted into an axial connector channel of connector header 220, such that respective proximal lead contacts engage with respective electrical contact systems within the channel. For example, upon insertion of the proximal end of the lead within the axial connector channel, the proximal lead contacts arranged at different axial positions along the length of the lead engage respectiveelectrical contacts arranged at different axial positions within the connector channel. The positioning and spacing, i.e., pitch, of the proximal lead contacts may correspond identically or partially to the positioning and spacing of the electrical contacts within the connector channel of the header. In this manner, the electrical contacts may electrically couple respective proximal lead contacts to respective terminals of circuitry within IMD 210. The proximal lead contacts, in turn, couple respective distal lead electrodes to the terminals via conductors within the lead body. The electrical contacts may be configured in accordance with various examples of this disclosure.

[0055] FIGS. 3A - 3C illustrate an example electrical contact system 350 configured to be disposed within the connector header 220 of the IMD 210 of FIGS. 2A - 2C. In some examples, electrical contact system 350 may be one of a plurality of electrical contact systems arranged at various axial positions along a longitudinal axis of a connector channel of connector header 220. The electrical contact system 350 provides an electrical connection between the IMD 210 and the lead 230. As discussed herein, electrical contact system 350 typically is disposed within the header of IMD 210 in order to enable IMD 210 to accept the proximal end of the medical lead. Electrical contact system 350 may be defined in part by a length 346 and an outer diameter. In some examples, the length 346 to diameter ratio may be 2: 1. In some examples, the length 346 to diameter ratio may be 2: 1 or greater. In some examples, the length 346 to diameter ratio may be 1:2. In some examples, electrical contact system 350 may have a contact member 320 and a housing 370. Housing 370 may have a ring shape and may further having a housing interior surface 372 and defined in part by longitudinal axis 374. The housing interior surface 372 of the housing 370 may be configured to receive the contact member 320 therein. FIG. 3B shows a first end of the electrical contact system 350. In some examples, the electrical contact system 350 may receive the proximal end of the lead from either end.

[0056] The electrical contact 320 (or a contact member) may have a general ring shape having a ring shaped wall 362 defined in part by an inner diameter and an outer diameter, and may be further defined by a contact longitudinal axis 358. In some examples, contact longitudinal axis 358 may be aligned with the housing longitudinal axis 374.

[0057] Electrical contact 320 may include at least one deflectable finger 340 (e.g., deflectable fingers 340A, 340B, and 340C) extending from the ring shaped wall 362 at a hinge portion 378 to a distal end 379. The at least one deflectable finger 340 may be coupled with thering shaped wall 362 at the hinge portion 378, and the at least one deflectable finger 340 may pivot along at least the hinge portion 378. Hinge portion 378 may refer to a portion of material along which bending may occur during deflection of deflectable finger 340. In some examples, the at least one deflectable finger 340 may deflect along the finger itself. In some examples, the at least one deflectable finger 340 may have a curved shape. In some examples, the at least one deflectable finger 340 may have a radius of about 0.025 inches (0.635 mm). In some examples, a clearance gap may surround a portion of the at least one deflectable finger 340 and to the remainder of ring shaped wall 362, as shown in FIG. 3C. In some examples, the distal end 379 of the at least one deflectable finger 340 may be disposed away from ring shaped wall 362 toward the contact longitudinal axis 358, and the distal end 379 may extend into the contact opening 364. In some examples, electrical contact 320 may include at least one deflectable V- shaped finger 340 extending from the ring shaped wall 362 into the contact opening 364, and having side edges. In some examples, electrical contact 320 may include at least two deflectable fingers. In some examples, electrical contact 320 may include at least three deflectable fingers. In some examples, the side edges of each deflectable finger 340 may be disposed at an angle relative to a central axis 382 of the at least one deflectable finger 340. In some examples, the at least one deflectable finger 340 is defined in part by a central axis 382, and the central axis is perpendicular to the housing longitudinal axis 374. In some examples, the side edges of each deflectable finger 340 may be disposed at an angle relative to the housing longitudinal axis 374. In some examples, one or more side edges may be disposed at a 45 degree angle to an insertion direction of the lead into the electrical contact system, where the insert direction may be aligned with the contact longitudinal axis 358. In some examples, one or more side edges may be disposed at a 30 - 60 degree angle to an insertion direction of the lead into the electrical contact system, where the insert direction may be aligned with the contact longitudinal axis 358. In some examples, one or more side edges may have a chamfer. In some examples, one or more side edges may by rounded.

[0058] In some examples, electrical contact 320 may include three deflectable fingers 340A, 340B, 340C that extend from ring shaped wall 362 into contact opening 364. In some examples, three fingers 340A, 340B, 340C are self-centering for a lead inserted into the electrical contact 320. In some examples, the three fingers 340A, 340B, 340C are symmetrically disposed around the ring shaped wall 362. In some examples, the at least one deflectable finger 340 comprises atleast two deflectable fingers that are self-centering for leads inserted into the electrical contact system 350. In one or more examples, the deflectable finger 340 has a spring bias configured to bias the finger 340 against a contact 240 (FIG. 2) of the lead 330 (which would be positioned at the dotted line). In some examples, the deflectable finger 340 extends from a hinge portion 378 to a distal portion 379, where the distal portion 379 is configured to contact the proximal lead contact 240 of the lead 330. In some examples, deflectable fingers may extend to a distal end 379, and the distal ends 379 may extend away from wall 362 toward the contact longitudinal axis 358 and may define a distal end diameter 356. Contact longitudinal axis 358 generally aligns with housing longitudinal axis 374. In some examples, the distal end diameter 356 may be smaller than an outer diameter of lead 330. In some examples, the lead 330 may deflect the distal end 379 of fingers 340 toward wall 362. In some examples, each finger 340 has an elastic limit higher than 0.9% and a modulus less than 13000 ksi. In some examples, V-shaped finger 380 has an elastic limit higher than 0.9% and a modulus less than 12000 -14000 ksi.

[0059] In some examples, electrical contact 320 is a stamped contact member. For example, the electrical contact 320 may be formed by stamping a strip of material into the contact member that is used to form electrical contact 320 of electrical contact system 350. In some examples, electrical contact 320 may be formed of one or more of titanium alloy or beta Ti alloy material, such as beta Ti alloy strip. After stamping, additional process may be performed on the stamped contact member such as bending of various portions to form deflectable fingers 340, protrusions (e.g., protrusions 390, 391, and 392 of FIG. 4 A), or curving to the final ring shape of electrical contact 320.

[0060] FIGS. 3D and 3E illustrate an example housing 370. Housing 370 may have a ring shape and may further have a housing interior 372 and defined in part by longitudinal axis 374. The housing interior 372 of the housing 370 may be configured to receive the electrical contact 320 (FIGS. 3A-3C), and the longitudinal axis 374 may be aligned with a longitudinal axis of the electrical contact 320. Together, electrical contact 320 and housing 370 may form electrical contact system 350 that may be disposed within an implantable medical device that can accept the proximal end of a medical lead. In some examples, housing 370 may be modified to accommodate varying lengths of the electrical contact.

[0061] FIGS. 4A, 4B, 4C, and 4D illustrate an example electrical contact 320. Electrical contact 320 includes spoon shaped fingers, but other example electrical contacts may includeother shaped fingers, such as a V-shaped finger or fingers of any other shape that may support the functionality described herein. FIG. 4A is an end view illustrating electrical contact 320 for an electrical contact system in accordance with one or more techniques of this disclosure.

[0062] As shown in FIG. 4A, electrical contact 320 may have a general ring shape having a ring shaped outer wall 322 defined in part by an inner diameter and an outer diameter, and may be further defined by a contact longitudinal axis 325. Outer wall 322 also includes an outer surface that is facing radially outward from outer wall 322 and an inner surface that is facing radially inward (e.g., toward channel 324). Electrical contact 320 may be configured to be disposed within housing 370 (FIGS. 3D and 3E). In some examples, contact longitudinal axis 325 may be aligned with the housing longitudinal axis 374 (FIG. 3E). Although outer wall 322 is shown as a ring shape (e.g., circular) in the example of FIG. 4A, outer wall may have other cross-sectional shapes in other examples, such as an oval, triangle, rectangle, square, polygon, or any other symmetrical or asymmetrical shape. In addition, these shapes may be general shapes that also include other features such as projections, overlaps, or other deviations from a true shape.

[0063] Electrical contact 320 may include at least one deflectable finger 340 (e.g., deflectable fingers 340A, 340B, and 340C) extending radially inward from the ring shaped wall 322 at a respective hinge portion 343 to a neck portion and then a respective distal end 359 (e.g., distal ends 359A, 359B, and 359C). The distal end 359 may have a rounded width and a curved surface having the outside of the curved surface facing radially inward. The width of the neck portion being narrower than the width of the rounded distal end 359. The at least one deflectable finger 340 may be coupled with the ring shaped outer wall 322 at the hinge portion 343, and the at least one deflectable finger 340 may pivot along at least the hinge portion 343. In some examples, the at least one deflectable finger 340 may deflect along the finger itself. Hinge portion 343 may be located closer to outer wall 322 than s-shaped portion 389. In other examples, hinge portion 343 may include some or all of s-shaped portion 389.

[0064] S-shaped portion 389 may be a bend or other shape that reduces the likelihood (or prevents) that a portion of deflectable finger 340 extends radially further from the outer surface of outer wall 322 when deflectable finger 340 is pushed outward from the insertion of a lead into channel 324. For example, s-shaped portion 389 includes a first portion defining a radially inward curvature 394 and a second portion defining a radially outward curvature 393, whereinthe second portion being distal from the first portion. Since radially inward curvature 394 directs deflectable finger 340 radially inward into channel 324, movement of deflectable finger 340 radially outward still does not cause hinge portion 343 (or other parts of deflectable finger 340) from being forced radially further than the outer surface of outer wall 322. S-shaped portion 389 (and radially inward curvature 394) thus can enable a larger portion of deflectable finger 340 to flex, or bend, in response to contact from an inserted lead. Without s-shaped portion 389, a further distal portion of deflectable finger 340 can contact the housing (e.g., housing 370) within which electrical contact 320 is disposed and reduce the length of deflectable finger 340 that can bend, which also increases stress and strain in the remaining portion of deflectable finger 340 that is still free to bend. Increased stress and strain can result in material fracture, plastic deformation, or other changes to bias force from deflectable finger 340 to the inserted lead. Therefore, s-shaped portion 389 can reduce stress, strain, and the likelihood of dysfunction or failure of deflectable finger 340.

[0065] In some examples, the at least one deflectable finger 340 may have a curved shape, such as a curve in the radially inward direction. In some examples, a clearance gap 342 may surround a portion of the at least one deflectable finger 340, as shown in FIG. 4B. In some examples, the distal end 359 of the at least one deflectable finger 340 may be disposed away from ring shaped wall 322 toward the contact longitudinal axis 325, and the distal end 359 may extend into the channel 324 (a contact opening). In some examples, electrical contact 320 may include at least one deflectable spoon shaped finger 340 extending from the ring shaped wall 322 into channel 324, and having side edges 341A, 341B. As shown, spoon shaped deflectable fingers 340 include a rounded end 359 and a neck proximal from the rounded end 359, wherein the neck is narrower than the rounded end 359, and wherein the rounded end 359 comprises a curved surface. The spoon shape of fingers 340 may provide a ramped surface to facilitate the insertion of the lead through electrical contact 320 and ramp up finger deflection as the lead is inserted.

[0066] In some examples, side edges 341 A, 341B may be disposed at an angle relative to a central axis 325 of the at least one deflectable spoon shaped deflectable finger 340. In some examples, the at least one deflectable spoon shaped deflectable finger 340 is defined in part by a central axis, and the central axis is perpendicular to the housing longitudinal axis that runs through the center lumen defined by ring shaped outer wall 322. In some examples, side edges341 A, 341B may be disposed at an angle relative to the housing longitudinal axis. In some examples, one or more side edges 341 A, 341B may be disposed at a 45 degree angle to an insertion direction of the lead into the electrical contact, where the insertion direction may be aligned with the contact longitudinal axis 325. In some examples, side edges 341 A, 341B may have a formed or stamped edge that facilitates lead insertion through reduced insertion forces as compared to a rounded or coined edge.

[0067] In some examples, the spoon shaped finger may have side edges that taper to a point. In some examples, electrical contact 320 may include at least two deflectable spoon shaped fingers that extend from ring shaped outer wall 322 into channel 324. In some examples, electrical contact 320 may include three deflectable spoon shaped fingers 340A, 340B, 340C that extend from ring shaped outer wall 322 into channel 324 In some examples, three spoon shaped fingers 340A, 340B, 340C are self-centering for a lead inserted into the electrical contact. For example, fingers 340A, 340B, 340C may be positioned and configured to guide the longitudinal axis of the lead into substantial alignment with the longitudinal axis 325 of the electrical contact. In some examples, the three spoon shaped fingers 340A, 340B, 340C are symmetrically disposed around the ring shaped outer wall 322. In some examples, the at least one deflectable spoon shaped finger 340 comprises at least two deflectable spoon shaped fingers that are self-centering for leads inserted into the electrical contact 320. In one or more examples, the deflectable spoon shaped finger 340 has a spring bias configured to bias the finger 340 against a contact 240 (FIG.2) of the lead 230, thereby providing contact pressure for reliable electrical interconnection. The deflectable finger 340 may be formed with a gap between the radially outside edge of finger 340 and the housing when inserted. The gap may be determined based on the bias force desired from fingers 340 to the lead and / or to reduce plastic deformation in fingers 340 after the lead is inserted into channel 324. In some examples, the size of the gap may in the range of about 0.05 mm to about 0.25 mm, but may be in a range of about 0.010 mm to about 0.013 mm, prior to lead insertion. The size of the gap may be dependent on several factors, such as finger length, finger thickness, and material selection. In some examples, the spoon shaped finger 340 extends from a hinge portion 343 to a distal portion 359, where the distal portion 359 is configured to contact the contact 240 of the lead 230.

[0068] In some examples, the length of deflectable finger 340 may selected to be as long as possible without interfering with the next finger around the circumference of ring shaped outerwall 322. In some examples, the thickness of deflectable finger 340 may be selected to achieve a target force and / or strain of deflectable finger 340. In some examples, the thickness of deflectable finger 340 may be in a range of about 0.02 mm to about 0.3 mm. In some examples, the thickness of deflectable finger 340 may be in a range of about 0.05 mm to about 0.15 mm, and in some example, the thickness of deflectable finger 340 may be approximately 0.10 mm.

[0069] In some examples, spoon shaped finger 340 has an elastic limit higher than 0.9% and a modulus less than 13000 ksi. In some examples, electrical contact 320 is a stamped contact member. For example, the electrical contact 320 may be formed by stamping a strip of material into the contact member of electrical contact 320. In some examples, electrical contact 320 may be formed of one or more of titanium alloy or beta Ti alloy material, such as beta Ti alloy strip. The beta Ti alloy may contain alloy elements such as Mo, Nb, Ta, Sn and Zr. The alloy can be Ti-15Mo, beta 21 S, Til5Mo5Zr3Al, beta C etc. The beta Ti alloy strip has to have beta phase fraction larger than 94%. The thickness of the beta Ti alloy strip is between 0.003” to 0.004” (about 0.076 mm to 0.102 mm). In some examples, the electrical contact 320 has an overlapping joint 348 where a first end of the electrical contact 320 overlaps a second end of the electrical contact 320. There may be a distance between wall end 323 and elbow 328. This distance, or gap in the outer wall, may allow the overlapping joint 348 to slide with respect to outer wall 322 such that the distance between wall end 323 and elbow 328 can change during insertion of electrical contact 320 into the housing. In some examples, this distance may be in the range of 0.025 millimeters (mm) to 0.26 mm before inserted within the housing, but that distance may decrease when installed into the housing. In one example, the pre-installed distance may be in the range of 0.050 mm to 0.100 mm, and in one example the pre-installed distance may be approximately 0.076 mm. In other words, this distance or gap between wall end 323 and elbow 328 may facilitate insertion of electrical contact 320 into the housing and retention during manufacturing of the device. In some examples, electrical contact 320 may be defined by a length 327 and a diameter 326, and a ratio of the length to diameter is less than 1: 1. In some examples, electrical contact 320 may be defined by a length 327 and a diameter 326, and a ratio of the length to diameter is less than 1:2.

[0070] Electrical contact 320 may also include one or more protrusions (e.g., protrusions 390, 391, and 392). Each protrusion may be configured to prevent a medical lead from moving a respective deflectable finger 340 of the plurality of deflectable fingers beyond a radial limit (e.g.,radial limit 397 of FIG. 4C) defined by the respective protrusion. For example, when the lead is inserted into channel 324, the lead can push each deflectable finger 340 radially outward. Each protrusion can be configured such that when the lead contacts the protrusion, the protrusion prevents the lead from moving further radially outward and moving a respective deflectable finger 340 radially further than the radially inner surface of the respective protrusion. As shown in the example of FIG. 4A, deflectable finger 340C can be moved beyond the radially inner surface of protrusion 390 until the lead contacts the radially inner surface 390 at which point the lead can no longer move deflectable finger 340C further radially outward. In this manner, protrusions 390, 391, and 392 can protect respective deflectable fingers 340 from plastic deformation (and the resulting decrease in bias force causing electrical contact between fingers 340 and respective contacts of the lead) that could occur without the respective protrusions. Generally, electrical contact 320 may include a protrusion for each respective deflectable finger. Moreover, each protrusion may be circumferentially aligned with a distal end (e.g., distal ends 359) of respective deflectable fingers 340. In some examples, not all deflectable fingers may have a respective protrusions and / or additional protrusions may be provided at locations without deflectable fingers (e.g., to facilitate centering of lead with respect to outer wall 322.

[0071] As shown in the example of FIG. 4 A, each protrusion 390, 391, and 392 is formed by a radially inward curve in outer wall 322 such that each protrusion can extend radially inward from the inner diameter of outer wall 322. FIG. 4C illustrates an example radius of curvature of the radially inward curve 395 in outer wall 322 that forms protrusion 390 (which may also be applicable to other protrusions such as protrusions 391 and 392). The radius of radially inward curve 395 is shown as 0.0040 inches (approximately 0.102 mm), but smaller or larger radii may be used in other examples. For example, the radially inward curve may have a radius of curvature from 0.05 mm to 0.6 mm. In addition, radially inward curve 395 may not be an exact circular curve and may have other shapes in other examples. The radially outward curves on either side of radially inward curve 395 may have matching radii, which may also math the radius of radially inward curve 395 in some examples. However, other radii and other shapes of the curves may be used in other examples. As shown in the example of FIG. 4C, protrusion 390 defines radially inner surface 396 which defines the radial limit 397. Radial limit 397 may be the distance from the contact longitudinal axis to the radially inner surface 396. The inner surface offinger 340C cannot be moved further radially outward than radial limit 397 because the lead will be stopped by inner surface 396 of protrusion 390.

[0072] In some examples, as shown in FIG. 4D, each protrusion defines a center channel 388 that separates two portions 390 A and 390B of respective protrusion 390. In this manner, portions 390A and 390B function to act as protrusion 390 that enables deflectable finger 340C to move into center channel 388 between portions 390A and 390B. In other examples, a protrusion may only have a single portion on one side of a respective deflectable finger and still prevent the lead from moving the finger beyond radial limit 397. Protrusions 390, 391, and 392 may be formed by bending a contact member that is stamped or otherwise formed at the location for the protrusions. Protrusion 392 may provide a similar radial limit (and similar radius of curvature) as other protrusions 390 and 391. However, protrusion 392 may be formed with different radius of curvature and / or different distances due to the proximity of protrusion 392 to overlapping joint 348. Therefore, although all protrusions may perform similar functions and / or provide similar stops for respective deflectable fingers 340, each protrusion may be formed or added differently and / or have different dimensions due to their location on / in outer wall 322.

[0073] In other examples, protrusions may be formed and / or added using other methods, such as described in FIGS. 4E and 4F. A single electrical contact may have protrusions that are all the same or have a mix of different protrusion types and / or sizes. As shown in the example of FIG. 4E protrusion 590 may be similar to protrusion 390 of FIG. 4C, such as establishing a similar radial limit 397. However, protrusion 590 may be formed with a sharp bend or crease 595 in outer wall 522 (which may be similar to outer wall 322). Crease 595 may be similar to a radially inward curve, but it may have a sharp bend caused by the method of forming which may include creasing a stamped contact member. Protrusion 590 can define inner surface 596 which establishes radial limit 397.

[0074] As shown in the example of FIG. 4F protrusion 690 may be similar to protrusion 390 of FIG. 4C, such as establishing a similar radial limit 397. However, protrusion 690 may be formed by adding material to the inner surface of outer wall 622 (which may be similar to outer wall 322). For example, protrusion 690 may be a volume of solder that is added to outer wall 622, material that is welded to outer wall 622, a thicker portion of outer wall 622, a portion of material that is added to the inner surface of outer wall 622 via adhesive or fixation element, or any other type of material. In any case, protrusion 690 can define inner surface 696 whichestablishes radial limit 397. A single electrical contact may include protrusions of all the same type or protrusions of two or more different types.

[0075] FIGS. 5 A and 5B illustrate a stamped contact member 490. Stamped contact member 490 may be curved into an electrical contact such as electrical contact 320, such as curved into a ring shape or other type of shape. In some examples, stamped contact member 490 has a thickness 494 of about 0.05 mm to 0.13 mm. In some examples, contact member 490 may comprise of a titanium alloy strip, beta Ti alloy strip material, or a beta Ti alloy strip. The stamped contact member 490 can be rolled into a tube to make the electrical contact with the three deflectable fingers. Each deflectable finger may include finger distal ends 484A, 484B, and 484C. In some examples each deflectable finger may also be bent to include one or more shapes, such as the spoon shape and / or s-shaped portion (e.g., s-shaped portion 389). For example portions 480A, 480B, and 480C may be bent into respective s-shaped portion 389.

[0076] In addition, as show in FIG. 5A, protrusions may be formed from portions 485A, 485B, and 485C. Each deflectable finger may have a length corresponding to length 486. Midline 492 indicates the middle of contact member 490. When rolled into an electrical contact, proximal end 496 can overlap with distal end 498. In some examples, the overlapping ends 496 and 498 are not connected together since the electrical contact will be disposed within a housing (e.g., housing 370). In other examples, overlapping ends 496 and 498 may be welded or otherwise coupled together.

[0077] FIG. 6 is a flow diagram illustrating fabricating an electrical contact, such as electrical contact 320. The electrical contact may include a contact member assembled within a housing. A strip of electrically conductive material, such as metallic material, may be used to form the contact member. In some examples, the strip of material may have a thickness of 0.05mm to 0.15mm. In some examples, the strip of material may include titanium alloy material. In some examples, the strip of material may include a beta Ti alloy strip.

[0078] A die may be used to stamp a contact member from the strip of material (500), to form a stamped strip 490, as shown in FIGS. 5A, 5B. As shown, the stamped contact member 490 may include three deflectable fingers 340. In some examples, the deflectable fingers are spoon-shaped and may processed to provide a beveled edge along the sides of the fingers. In some examples, high pressure stamping die may cause plastic deformation to edges and provides a beveled or rounded edge. In some examples, the deflectable fingers are formed into shapewhere deflectable fingers are bent away from the planar strip. In some examples, progressive die stamping may be used to create a bend and / or radius in the deflectable fingers. Progressive die stamping or another technique may also be used to create s-shaped bends in each deflectable fingers and / or protrusions in the outer wall of the contact member as described herein. In some examples, stamped contact member 490 has a thickness 494 of about 0.05 mm to 0.13mm. In some examples, contact member 490 may comprise of a titanium alloy strip, beta Ti alloy strip material, or a beta Ti alloy strip.

[0079] The stamped contact member 490 may be rolled into a ring shape (502) to form an electrical contact. For example, the ring shape of the electrical contact may be similar to the ring shape of electrical contact 320 in FIGS. 4A-4C. In some examples, rolling the stamped contact member 490 may include overlapping a portion of a first end 496 of the stamped contact member 490 over a second end 498 of the stamped contact member 490. In one or more examples, the stamped contact member 490 is rolled into a ring shape and secured in place. In one example, the stamped contact member 490 may be overlapped and welded at a weld joint. The method further may include disposing the rolled contact member into a housing to form an electrical contact (504). Prior to or after rolling, s-shaped portions may be formed into each deflectable finger and / or protrusions may be formed in, or added to, the outer wall of the stamped contact member 490. The electrical contact 250 may further be disposed within a terminal 222 within a connector header 220 of an IMD 210 (FIG. 2) to facilitate the electrical connection between the lead 230 and the IMD 210 when the lead 230 is disposed within the terminal of the IMD 210.

[0080] The following examples are described herein.

[0081] Example 1 : An electrical contact for coupling a contact of a medical lead with electronics of a medical device, the electrical contact comprising: an outer wall defining a contact longitudinal axis and comprising an inner surface and an outer surface, wherein the inner surface defines a contact opening; a plurality of deflectable fingers extending radially inward from the outer wall and into the contact opening defined by the inner surface of the outer wall, wherein: the outer wall comprises a plurality of protrusions, each respective protrusion of the plurality of protrusions is configured to prevent the medical lead from moving a respective deflectable finger of the plurality of deflectable fingers beyond a radial limit defined by the respective protrusion; and the electrical contact is configured to be disposed within a housingdefining a housing longitudinal axis such that the contact longitudinal axis is aligned with the housing longitudinal axis.

[0082] Example 2: The electrical contact of example 1, wherein each protrusion of the plurality of protrusions is formed by a radially inward curve in the outer wall.

[0083] Example 3: The electrical contact of example 2, wherein the radially inward curve has a radius of curvature from 0.05 mm to 0.6 mm.

[0084] Example 4: The electrical contact of any of examples 1 through 3, wherein each protrusion of the plurality of protrusions is circumferentially aligned with a distal end of the respective deflectable finger of the plurality of deflectable fingers.

[0085] Example 5: The electrical contact of any of examples 1 through 4, wherein each protrusion of the plurality of protrusions defines a center channel separating two portions of the respective protrusion, wherein the central channel is configured to accept at least a portion of the respective deflectable finger.

[0086] Example 6: The electrical contact of any of examples 1 through 5, wherein each deflectable finger of the plurality of deflectable fingers defines a first portion comprising defining a radially inward curvature and a second portion defining a radially outward curvature, the second portion being distal from the first portion.

[0087] Example 7: The electrical contact of any of examples 1 through 6, wherein the plurality of deflectable fingers comprises at least three deflectable fingers extending from the outer wall.

[0088] Example 8: The electrical contact of any of examples 1 through 7, wherein each deflectable finger of the plurality of deflectable fingers has a spring bias configured to bias the deflectable finger against a contact of the medical lead.

[0089] Example 9: The electrical contact of any of examples 1 through 8, wherein each deflectable finger of the plurality of deflectable fingers comprises a rounded end and a neck proximal from the rounded end, wherein the neck is narrower than the rounded end, and wherein the rounded end comprises a curved surface.

[0090] Example 10: The electrical contact of any of examples 1 through 9, wherein the contact member is constructed from a stamped metal alloy material.

[0091] Example 11 : The electrical contact of example 10, wherein a thickness of the stamped metal alloy material is from 0.05 mm to 0.13 mm.

[0092] Example 12: The electrical contact of any of examples 1 through 11, wherein the outer wall is ring shaped, and wherein the housing is ring shaped.

[0093] Example 13 : The electrical contact of any of examples 1 through 12, wherein the housing comprises a curved shape defining an opening therein, the opening configured to receive the contact member therein, wherein the housing is defined in part by the housing longitudinal axis and a housing inner diameter.

[0094] Example 14: An implantable medical device configured to deliver electrical stimulation therapy, the medical device comprising: an electronics housing having a connector header; an electrical contact disposed within the connector header, the electrical contact configured for coupling a medical lead with electronics of the medical device configured to deliver electrical stimulation therapy, the electrical contact comprising: an outer wall defining a contact longitudinal axis and comprising an inner surface and an outer surface, wherein the inner surface defines a contact opening; and a plurality of deflectable fingers extending radially inward from the outer wall and into the contact opening defined by the inner surface of the outer wall, wherein the outer wall comprises a plurality of protrusions, and wherein each respective protrusion of the plurality of protrusions is configured to prevent the medical lead from moving a respective deflectable finger of the plurality of deflectable fingers beyond a radial limit defined by the respective protrusion; and a housing defining an opening therein, the opening configured to receive the electrical contact therein, wherein the housing is defined in part by a housing longitudinal axis and a housing inner diameter, and wherein the electrical contact is configured to be disposed within the housing such that the contact longitudinal axis is aligned with the housing longitudinal axis.

[0095] Example 15: The medical device of example 14, wherein a proximal end of the medical lead is disposed within the connector header and includes a contact configured to engage the electrical contact.

[0096] Example 16: The medical device of any of examples 14 or 15, wherein the electrical contact is one electrical contact of a plurality of electrical contacts, the plurality of electrical contacts arranged at different positions within the housing to engage respective proximal lead contacts of a plurality of proximal lead contacts of the medical lead.

[0097] Example 17: The medical device of any of examples 14 through 16, wherein each protrusion of the plurality of protrusions is formed by a radially inward curve in the outer wall.

[0098] Example 18: The medical device of any of examples 14 through 17, wherein each protrusion of the plurality of protrusions defines a center channel separating two portions of the respective protrusion, wherein the central channel is configured to accept at least a portion of the respective deflectable finger.

[0099] Example 19: The medical device of any of examples 14 through 18, wherein each deflectable finger of the plurality of deflectable fingers defines a first portion comprising defining a radially inward curvature and a second portion defining a radially outward curvature, the second portion being distal from the first portion.

[0100] Example 20: A method for forming an electrical contact comprising: stamping an electrical contact from a strip of material; forming a plurality of deflectable fingers from the strip of material; forming a plurality of protrusions from the strip of material; forming the stamped contact member into a ring shaped wall defining a longitudinal axis and comprising an inner surface and an outer surface, the inner surface defining a contact opening, wherein: the plurality of deflectable fingers extend radially inward from the outer wall and into the contact opening defined by the inner surface of the outer wall; the outer wall comprises the plurality of protrusions, wherein each respective protrusion of the plurality of protrusions is configured to prevent a medical lead from moving a respective deflectable finger of the plurality of deflectable fingers beyond a radial limit defined by the respective protrusion; and the electrical contact is configured to be disposed within a housing defining a housing longitudinal axis such that the contact longitudinal axis is aligned with the housing longitudinal axis.

[0101] The techniques described in this disclosure may be implemented, at least in part, in hardware, software, firmware or any combination thereof. For example, various aspects of the described techniques may be implemented within one or more processors or processing circuitry, including one or more microprocessors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), or any other equivalent integrated or discrete logic circuitry, as well as any combinations of such components. The term “processor” or “processing circuitry” may generally refer to any of the foregoing logic circuitry, alone or in combination with other logic circuitry, or any other equivalent circuitry. A control unit including hardware may also perform one or more of the techniques of this disclosure.

[0102] Such hardware, software, and firmware may be implemented within the same device or within separate devices to support the various operations and functions described in thisdisclosure. In addition, any of the described units, circuits or components may be implemented together or separately as discrete but interoperable logic devices. Depiction of different features as circuits or units is intended to highlight different functional aspects and does not necessarily imply that such circuits or units must be realized by separate hardware or software components. Rather, functionality associated with one or more circuits or units may be performed by separate hardware or software components or integrated within common or separate hardware or software components.

[0103] The techniques described in this disclosure may also be embodied or encoded in a computer-readable medium, such as a computer-readable storage medium, containing instructions that may be described as non-transitory media. Instructions embedded or encoded in a computer-readable storage medium may cause a programmable processor, or other processor, to perform the method, e.g., when the instructions are executed. Computer readable storage media may include random access memory (RAM), read only memory (ROM), programmable read only memory (PROM), erasable programmable read only memory (EPROM), electronically erasable programmable read only memory (EEPROM), flash memory, a hard disk, a CD-ROM, a floppy disk, a cassette, magnetic media, optical media, or other computer readable media.

Claims

WHAT IS CLAIMED IS:

1. An electrical contact for coupling a contact of a medical lead with electronics of a medical device, the electrical contact comprising: an outer wall defining a contact longitudinal axis and comprising an inner surface and an outer surface, wherein the inner surface defines a contact opening; a plurality of deflectable fingers extending radially inward from the outer wall and into the contact opening defined by the inner surface of the outer wall, wherein: the outer wall comprises a plurality of protrusions, each respective protrusion of the plurality of protrusions is configured to prevent the medical lead from moving a respective deflectable finger of the plurality of deflectable fingers beyond a radial limit defined by the respective protrusion; and the electrical contact is configured to be disposed within a housing defining a housing longitudinal axis such that the contact longitudinal axis is aligned with the housing longitudinal axis.

2. The electrical contact of claim 1, wherein each protrusion of the plurality of protrusions is formed by a radially inward curve in the outer wall.

3. The electrical contact of claim 2, wherein the radially inward curve has a radius of curvature from 0.05 mm to 0.6 mm.

4. The electrical contact of any of claims 1 through 3, wherein each protrusion of the plurality of protrusions is circumferentially aligned with a distal end of the respective deflectable finger of the plurality of deflectable fingers.

5. The electrical contact of any of claims 1 through 4, wherein each protrusion of the plurality of protrusions defines a center channel separating two portions of the respective protrusion, wherein the central channel is configured to accept at least a portion of the respective deflectable finger.

6. The electrical contact of any of claims 1 through 5, wherein each deflectable finger of the plurality of deflectable fingers defines a first portion comprising a radially inward curvature and a second portion defining a radially outward curvature, the second portion being distal from the first portion.

7. The electrical contact of any of claims 1 through 6, wherein the plurality of deflectable fingers comprises at least three deflectable fingers extending from the outer wall.

8. The electrical contact of any of claims 1 through 7, wherein each deflectable finger of the plurality of deflectable fingers has a spring bias configured to bias the deflectable finger against the contact of the medical lead.

9. The electrical contact of any of claims 1 through 8, wherein each deflectable finger of the plurality of deflectable fingers comprises a rounded end and a neck proximal from the rounded end, wherein the neck is narrower than the rounded end, and wherein the rounded end comprises a curved surface.

10. The electrical contact of any of claims 1 through 9, wherein the contact member is constructed from a stamped metal alloy material.

11. The electrical contact of claim 10, wherein a thickness of the stamped metal alloy material is from 0.05 mm to 0.13 mm.

12. The electrical contact of any of claims 1 through 11, wherein the outer wall is ring shaped, and wherein the housing is ring shaped.

13. The electrical contact of any of claims 1 through 12, wherein the housing comprises a curved shape defining an opening therein, the opening configured to receive the contact member therein, wherein the housing is defined in part by the housing longitudinal axis and a housing inner diameter.

14. An implantable medical device configured to deliver electrical stimulation therapy, the medical device comprising: an electronics housing having a connector header; the electrical contact of any of claims 1 through 13; and a housing defining an opening therein, the opening configured to receive the electrical contact therein, wherein the housing is defined in part by a housing longitudinal axis and a housing inner diameter, and wherein the electrical contact is configured to be disposed within the housing such that the contact longitudinal axis is aligned with the housing longitudinal axis.

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