Project Partner Interview Summary

Date: April 3, 2024

Time: 8:00-8:30 a.m.

Location: Virtual (Zoom)

Team members in attendance: Sydney Smith, Kay Tu

Project Partner/Design Problem Overview

• Client name: Michelle Urban

• Profession/Qualifications: physical therapist, clinical supervisor

• Organization: Shriners Children’s Chicago

• Contact information: murban@shrinenet.org 

Overview

Ms. Michelle Urban, a physical therapist and clinical supervisor at Shriners Children’s Chicago, presented the design problem. While there are multiple facets of the problem that Shriners Children’s experiences with their halo traction equipment, the main issues relate to a specific clamp that is used on all models of the equipment that they currently use. The clamp is no longer manufactured, and it does not correctly fit all of the walkers and wheelchairs that they currently use. In addition, after repeated attachments and removals, the screws on the clamp become worn and become stripped of their material. Another primary issue that may be considered is the imbalance of weight distribution throughout the walkers, which present safety issues, as well as difficulty of use, while patients use the devices.

Key Points

• The clamp that is used to stabilize the walkers and wheelchairs is no longer being manufactured

• The clamp does not fit all of the necessary parts properly

• The clamp becomes worn out and stripped of its material after normal-wear and tear

• The weight distribution of the wheelchairs and walkers is uneven because of the boon, which present safety issues

Users

The halo traction equipment is primarily used on children with scoliosis or similar spinal formation problems. While some patients have flexible spinal curves, which allows them to immediately receive a spinal fusion to remedy the problem, others are not as flexible, and they must undergo halo traction therapy before surgery. At any given time, approximately four to five patients are using these devices, but Shriners wishes to increase the number of patients they are able to offer this treatment to. 

Device Use and Function

Halo-Traction Setup

The halo-traction device contains four main components, which include either a walker or wheelchair, a ring that is connected to the patient’s forehead through pin attachments, a v-shaped boon that is attached to the back of the walker/wheelchair, and a rope and pulley system to weight the patient down and ultimately stretch their spines. The wheelchair and walker setup can be viewed in Figure 1 below, and the structure of the wheelchair itself and the boon connected to the wheelchair can be viewed in Figure 2 and Figure 3, respectively. As seen in Figures 2 and 3, the boon connects to the back of the wheelchair and comes forward towards the front in a v-shape. It connects a rope that hangs down over the back of the device and comes around to the front, where it contains an “s” hook, which then connects to the ring around the patient’s head. The halo-traction equipment can be difficult to set up, especially when adjusting the settings for different sized patients, so ideally the setup process for any design modifications would not be time consuming (5-10 minutes maximum). 

Figure 1: Wheelchair and Walker Setup

Figure 2: Wheelchair Setup

Figure 3: Wheelchair Boon Setup

Mobility

Patients should be able to perform normal tasks on a day-to-day basis while using the walker, with the primary mobility criteria being able to walk around easily. Many patients, especially younger patients, enjoy performing mild physical activity while in the walker, including running and jumping. The wheelchair is a secondary device used as another method of mobility and transportation if the patient prefers to not be in the walker; this mainly applies to their older teenage patients who usually do not like to be in the walker as often as younger patients. If a patient has limited mobility due to the nature of their spinal injury, however, their primary method of mobility will be the wheelchair. 

A common problem that the project partner recognizes is that the walkers are too heavy for most patients. Thus, when designing a solution for this problem, one main concern is the weight of the walkers, ensuring that they are not too heavy which would result in limited patient mobility. Ideally, any addition to the current device would not exceed a couple of pounds.

A current solution that Shriners Children’s has a supply of and utilizes is a Zimmer traction piece, which allows for greater ease of mobility on their walkers and wheelchairs.

Primary Issues

There are six current issues with the device that the project partner brought to our attention, which are listed below.

Circular Clamp Attachment

There is a circular clamp that attaches to the frame of both the wheelchairs and walkers and is a part of the overall structural support system. A common issue with this clamp is that over time, the screws become stripped of their material and do not always fit properly on the rods they are attached to. This piece is currently welded, but their former supplier is no longer able to make this piece for Shriner Children’s, so they are having trouble replacing the part when it no longer functions properly. Each walker uses four of these defective parts, and while they do have a surplus of different parts, not all of the pieces they have in stock stabilize and attach to the device properly. The clamp attachment can be viewed in Figure 4, Figure 5, and Figure 6 below.

Figure 4: Circular Clamp Attachment

Figure 5: Properly Fitting Circular Clamp

Figure 6: Improperly Fitting Clamp Attachment

Weight Distribution

Another main issue of both the wheelchairs and walkers is that because of the hardware on the back of the device, including the boon and pulley system, the device gets back heavy thus resulting in uneven weight distribution. Currently, Shriner’s Childrens attaches weights to the front of the device, attaching it with either the velcro connected to cuff-weights, coflex tape, or clamps. Depending on the wheelchair or walker design, however, the weights sometimes get in the way of the wheels in the front of the device, which is shown in Figure 7 and Figure 8 below.

Figure 7: Cuff-Weight Attached to Wheelchair with Tape

Figure 8: Cuff-Weight Attached to Walker with Clamp

  Size Adjustments and Accommodations

Another primary issue of the wheelchairs and walkers Shriner Childrens’ uses is their limited adjustable features. Because they provide this treatment to a wide variety of ages of children and young adults, the wheelchairs and walkers need to be able to fit a variety of patient sizes safely and effectively. While some pieces are swappable, this process is time consuming and can wear down and damage the pieces. Michelle wishes for there to be a more universal type design that could be easily adjustable to fit all of the patients that she serves. Shriners Childrens’ currently employs crocodile gait trainers on some of their devices, which have a longer base, adjustable handles (in terms of height), as well as offering a more stable and smooth ride. While size 1 and size 2 crocodiles are available and easily adjustable, size 3 crocodiles require a different device setup and thus don’t work on the existing systems that they have in their possession.

Wheelchair Boon Design

Michelle also expressed issues with the boon of the device, specifically the wheelchair. While the boon is at a diagonal angle to accommodate for height, she believes the angle that it is at is too drastic as it doesn’t come forward enough to properly fit the ring on the patient’s head. Thus, there is not a lot of room to move the pulley forward and back to try and get a vertical pull on the patient’s spine. 

Storage

While not mentioned as a primary issue, Michelle expressed that Shriners Children’s currently stores all of the halo traction devices in a wheelchair room that takes up a lot of space. 

Product Durability

The current devices which Shriners Children’s uses are at least seven years old now, and they are most likely nearing the end of their use. Michelle expressed that they wish to continue performing these procedures on children for years to come and that product durability is a key issue for them as they need a product to last a longer amount of time so they do not have to keep finding suppliers for the unique parts they employ every time they wear down or break. Ideally, the device would last a lifetime, but if a design can be formed that lasts over a decade, this would still result in great improvement from the equipment they have now. 

Estimated Budget

Michelle stated that there is currently no budget for this equipment, but that if they do establish one, it will most likely come out of their rehab budget. She will discuss with her director to gain more information about this. 

Analysis and Conclusion

Overall, Shriners Children’s is looking for a better setup and design/material construction of their halo traction devices to increase product durability and safety. Possible next steps for this design project will most likely include collaboration with the other teams assigned to this project as we each decide to focus on one aspect of the design problem. In-person user observations and testing will also be necessary to fully understand how this equipment works and what changes need to be made in order to successfully design a long-lasting, safe, and functional product.