Designing Virtual Reality for Pain Reduction

Imagine suffering a serious burn. The pain is unlike any you have ever felt. As you are rushed to the hospital for stabilization, in the throes of one of the worst moments of your life, you are only at the beginning of an agonizing journey.

After your initial treatment, you arrive at a hospital burn center for weeks or months of ongoing care. Especially in the beginning, this treatment can be just as excruciating as the initial injury. It includes removing the bandages from the burns and scrubbing them, before applying ointment and replacing the dressing. The process can last for up to two hours and it must take place every day, sometimes twice a day, in order to protect your burned flesh from infection. In addition, you will likely need operations. The pain is relentless, and even as it slowly improves, mental scars remain.

The acute injury of a burn — followed by the days, weeks, or months of frequent wound care and dressing changes — is one of the most painful things a patient can experience. Opioid pain medications, the mainstay of pain management, have well known short and long-term side effects. Despite these medications, pain often remains inadequately controlled in burn patients.

Alternative measures for pain control, including distraction, are known to be effective. Numerous studies have demonstrated that the immersive environment of virtual reality is a highly effective method of distraction for burn patients receiving wound care. However, virtual reality is not widely used in clinical practice outside of research studies, because many of these systems are customized and expensive. Emerging systems such as the Samsung Gear VR and Oculus Rift dramatically increase access to virtual reality, but even these may be too expensive for clinical settings, particularly if they are only used with a single-patient to minimize infection control concerns.

Google Cardboard presents an opportunity to pair nearly ubiquitous smartphones with an inexpensive cardboard box and lenses, in order to create a virtual reality system suitable for healthcare. However, existing Google Cardboard headsets are not designed for a moist burn wound care environment. Furthermore, most existing games are designed with the assumption that the user is upright and able to move about in an environment allowing for six degrees of freedom, which is not feasible in patients receiving burn wound care.

At frog we saw this as a design challenge: understand the opportunities and constraints involved with burn wound care and design a low-cost headset and VR game experience suitable for these conditions. Together with Dr. Brian Pridgen, a healthcare design fellow at frog and a Stanford Plastic and Reconstructive Surgery resident, we approached this challenge as a multidisciplinary team. The outcome of this passion project will be an inexpensive headset concept that is extremely affordable, easy to assemble, and feasible for use in the burn wound care environment. In addition to the headset, we are developing an open-source game concept, “Ēpiónē”, for use by burn patients. Our hope is that it can serve as a platform or template that other developers could use to build additional VR experiences for patients. The game will allow the patient to remain appropriately positioned for burn wound care while being immersed in a distracting virtual reality environment.

While working on this concept, the project team assembled a list of design principles that we share in detail below. The principles emerged through design and development of both the hardware and software, and they take into consideration the design constraints we documented through on-site research, interviews with nurses and patients, and user testing. The principles may be generally applicable to VR use in healthcare applications, but they were created with burn patients in mind. In the spirit of making healthcare solutions accessible as widely as possible, we’re sharing them below for anyone who is designing or building solutions in this space.

Headset

A number of design constraints dictated the need to explore a custom VR headset solution. It needed to be very low-cost, built using a durable and water-resistant material, and comfortable for the patient. Ideally the design would be easy to assemble from pieces that would allow it to be flat-packed for efficient distribution. The following are specific principles that guided our headset design.

Cheap to manufacture – Hospitals have limited funding, and relying on insurance companies for funding creates a barrier. If headsets are $30 or less (we aimed for $10 or less), hospitals are more likely absorb the cost for the patient benefit. If the cost is low enough, the headsets can be provided to each patient, minimizing infection control concerns that might otherwise be a barrier to adoption.

Water Resistant – Before removal, the patient’s bandages are soaked with slow moving warm water from a hose, which is controlled by a nurse. There may be some indirect contact with water. It is okay if the headset gets wet, but the device inside should be protected.

Patient Comfort – The most painful part of the cleaning procedure can last up to two hours. The patients are often lying down, but may sit up as well. Materials, weight, form, and adjustability to head sizes should be carefully considered.

Accessible to nurses – It should be easy for a nurse to access the device inside the headset while the patient is wearing it, without having to remove the entire headset.

Device Agnostic – Since each patient may receive a headset, it should accommodate a wide range of devices. A desired range might include devices with 4-inch to 6-inch screens.

Intuitive assembly and operation – Assembly and phone insertion should require as little instruction as possible. Devices of any size must be properly aligned/centered to avoid double vision while looking through lenses. A guideline on the headset, combined with alignment cues in the app could help with centering the device.

Eco-friendly – Where possible, environmentally friendly materials should be used to reduce environmental impact. Easily replaceable parts should be considered to avoid having to replace the entire headset.

Delightful – Burn patients undergo severe physical pain and emotional stress. Any way to induce positive feelings throughout the entire experience — from assembly to after the patients return home — should be explored. Consider personalization.

Software

The most important design principles for the game software address the lack of functional VR applications that work when someone is lying down, as many burn patients do while undergoing wound care. As the patient prepares for their procedure, they may have little opportunity to start the game experience themselves because they are connected to IVs, monitoring devices, and oxygen, so they will require assistance from nurses. The game experience must also be forgiving to allow for different types of players that have varying levels of familiarity with VR, and games in general.

Admin for Nurses or Doctors – An admin mode should allow nurses to adjust game settings, volume, brightness and alignment before the procedure starts. After assisting with these settings, the staff should be able to easily initiate the VR experience as they align the device in the headset, so the patient can avoid exiting gameplay during the procedure.

Allow for supine position – Most VR games will not play correctly if the player is lying down, because the device assumes the player is standing/sitting and looking up.

Calibration – Burn patients are often lying down, which the device’s accelerometer must accommodate. Once the phone has been inserted in the headset, the game should allow the user a moment to hold their head still while pointed forward, in order to establish a reference point for rotation.

Accommodate limited head mobility with head-tracking-only controls – Patients lying down can only comfortably move their head slightly to the left and right. Vertical up/down head movement is more restricted.

Age-friendly – Patients will be of all ages, demographics, and interests. Game content, including visual style and story, should be as inclusive as possible.

Challenging for all experience levels – Patients may have no video game experience, or a lot. Pain medication may also impair the patient’s ability to concentrate. After the initial difficulty level is selected from the admin menu, difficulty should continue to increase over time.

Reduce eye strain – Long exposure to bright colors will cause eye fatigue, so limit use of bright colors in the game world. Setting hardware brightness correctly before gameplay is key.

Forgiving gameplay – Gameplay should be forgiving across all difficulty levels. Players should be given second chances to correct their mistakes (which may be out of their control due to wincing from pain, or a nurse asking them to move). A regenerating shield is an example of a useful game mechanic that accomplishes this goal, and even produces unpredictable periods of suspense that add to the interest of the game.

Audio – Place sounds in physical locations around the player position. Make sure audio includes appropriate and immersive sound effects and background music loops. The audio should be nearer to higher frequencies since low bass tones are sometimes inaudible on standard mobile device speakers.

Conclusion

frog assembled these principles during active development and testing of the VR Care headset and custom game experience, which is available here as an APK file and an open source Unity package. The headset is now being used as part of an ongoing study with burn patients. This work is an example of the power of partnerships between medicine and design, with the potential to produce solutions that increase access to affordable virtual reality for patients. We hope that this work will serve as a model for future medicine-design partnerships to identify clinical needs, design practical solutions, and bring these solutions back to patients and the healthcare system. Feel free to leave us questions in the comments section and click here to get in touch about working with frog.