Rechargeable External Battery for Spinal Cord Stimulator

Chronic pain patients may suffer from Failed Back Surgery Syndrome (FBSS), intractable low back pain and leg pain, Peripheral Diabetic Neuropathy (PDN), or Nonsurgical Back Pain (NSBP). As a last resort, these patients may seek out relief from Spinal Cord Stimulators (SCS), which are implanted under the skin of the lower back. To reduce bulkiness of the implant, the battery is removed, and power must be supplied through an external battery that is worn over the area of the implant.

This research study sought to explore early-stage designs of the external battery and options for holding the external battery in place over the implant area. These options included a fabric belt and adhesive patch. Areas of interest were:

• Can users correctly place the external battery over the area of the implant with minimal instructions?

• What are the initial impressions of the fabric belt and adhesive patch?

• Do users have concerns about the ability of the fabric belt and adhesive patch to hold the external battery in place?

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Since the external battery has audible feedback and has to be placed on the user's back, recruitment targets included patients with dexterity and hearing issues. Participant comments and performance were analyzed and summarized in a formal report.

Data was collected via a usability study, where participants used the think-aloud method. They were asked to place and secure the external battery over a simulated implant on their lower back using both the fabric belt and adhesive patch. If any difficulty or issues were observed, study personnel (myself and another colleague) asked probing questions to determine what caused the issues. We also interviewed participants to gather their opinions about the fabric belt and adhesive patch's designs (e.g., color, material), which one they would prefer to wear if going out in public, and how the designs could be improved.

Based on observations and participant feedback, some findings included:

• Participants were not able to place the external battery with the current instructions. After a quick verbal explanation and visual demo, they were able to place the external battery. Therefore, the language in the instructions should be adjusted to more clearly explain the process of correctly placing the external battery--alternatively, patients can be provided with a short training video or quick verbal explanation from their doctor.

• Participants were concerned about the external battery falling out of the fabric belt pouch. Suggestions included a velcro or zipper fastener on the pouch.

• Participants liked that the fabric belt and adhesive patch were "invisible" -- they can be hidden under clothes when going out in public. Additionally, they are comfortable to wear.