Wearable Brain Computer Interface (BCI) to Assist Communication in Mechanically Ventilated Patients the Intensive Care Unit (ICU)

BACKGROUND

An inability to consistently and effectively communicate their most fundamental physical needs is a major problem for mechanically ventilated ICU patients. Patients rate about 40% of communication sessions as difficult and more than a third of communications about pain as unsuccessful. Nurses initiate about 86% of all communication exchanges as it is typically very difficult for a voiceless ICU patient to initiate communication. Patients in the ICU therefore commonly suffer unrecognized pain and discomfort, feelings of loss of control and insecurity, depersonalization, anxiety, sleep disturbances, fear and frustration. Caregivers also frequently report feeling anxious and frustrated in not being able to adequately assess the needs of their patients. This inability to communicate effectively can lead to the inappropriate use of sedatives and prolongation of time spent on the ventilator, which may then lead to increased ICU length of stay and costs. Furthermore, the inability to communicate with caregivers hampers the ability of critically ill patients to be active participants in their treatment and in decision-making, including decisions to withdraw or withhold life-sustaining treatment.

The use of picture boards with icons representing common patient needs and complaints (pain, fear, hot/ cold, thirst, bedpan etc) has been shown to improve nurse-patient communication for patients in the postoperative period on the ventilator. These picture boards are widely available in most ICUs and are the closest thing to a current standard for communication with voiceless mechanically ventilated patient, for the purposes of addressing fundamental physical and emotional needs. Recent pilot studies have described the use of computer-assisted communication using touch sensitive screens, eye blink detectors and gaze trackers to enable communication in the ICU patient. The majority of patients and hospital staff surveyed in these studies indicated that the use of a computer-assisted communication device improved the ability to respond to patient needs and address patient comfort. Gaze and eye blink tracker systems are expensive, however, while touch sensitive screens may not be suitable for the many ICU patients with weakness and restriction in motor ability. Patients in the ICU, particularly those with neurological illness, frequently suffer from significant weakness and loss of co-ordination, however, limiting their ability to use their arms and hands to indicate the appropriate item on the board. While patients in the neuroICU are frequently weak because of focal brain injury, about a quarter of patients requiring mechanical ventilation in other ICUs may have significant weakness from critical illness neuropathy and myopathy, limiting their ability to use their hands to select the appropriate icon on a picture board. There are several patient populations, however, for whom the use of a picture board or touch screen is impossible, including patients with high spinal cord injury, advanced ALS and brainstem stroke, who are voiceless, but also typically have no useful motor function of their limbs. These patients are "locked-in", to varying degrees, awake and alert but with no control of bodily function or ability to articulate and communicate using standard forms of communication.

The use of Brain Computer Interface (BCI) devices to facilitate communication in "voiceless" patients has recently generated interest. A BCI translates deliberate, voluntary modulation of cerebral electrical activity, typically recorded by electroencephalography (EEG) into computer commands. A variety of BCI devices have been used to permit patients with advanced Amyotrophic Lateral Sclerosis (ALS), high spinal cord injury and brainstem stroke with the locked-in-syndrome, who have no voluntary use of their limbs, to communicate to varying degrees. These devices have typically been evaluated in the rehabilitation setting, following the period of acute medical illness, or at home. No study has evaluated the use of a BCI device to assist with communication of the typical physical and emotional needs/ complaints of the critically ill. This is significant, not only for patients with spinal cord injury and stroke, most of who are initially admitted to an ICU, but to the potentially large number of ICU patients who cannot use a picture board or other finger contact system because of critical illness neuropathy/ myopathy or acute brain injury causing weakness. Our focus is on creating a steady state visual evoked potential (SSVEP) based, wireless BCI system to facilitate communication with intubated ICU patients., The wearable BCI device of interest in this study functions through visual attention to illustrative icons displayed on an electronic screen. The icon, which may depict a common ICU patient need, such the need for repositioning or common patient complaint, such as pain, can be displayed as a symbol. The patient can, thereby, communicate by looking at a specific item depicting their need or complaint. This wearable device is entirely noninvasive and without significant risk to patients, functioning only to record and translate EEG signals. The device will communicate wirelessly with the user interface (UI) that can be either a tablet or the flat screen TV monitor that is present in every ICU patient room. The proposed prototype provides a user interface that includes basic functions that are typically used in communication between nurses and patients in the ICU.

STUDY DESIGN