The purpose of this study is to evaluate the effectiveness of the CGX/Lucidify EEG system in enabling physicians to detect delirium (confusion) in medically ill patients as early as possible in order to minimize the detrimental effects of delirium. The study will involve collecting EEG data through the CGX EEG system (a Research-grade 2-Channel EEG device) and applying the Lucidify EEG software algorithm to identify indicators and degree of delirium, obtain data regarding the amount and degree of patient's movement and activity throughout the day in order to detail delirium subtype, and obtain data regarding the quality of the sleep as it affects delirium severity and duration. By enhancing early detection, this research aims to improve patient outcomes and inform clinical decision-making.

Study investigators would like to use a portable electroencephalogram (pEEG), the CGX EEG system (a Research-grade 2-Channel EEG device) to measure the brainwaves of patients admitted to Stanford Medical Center. Study investigators will then use the Lucidify software to allow for the interpretation of obtained brainwaves in order to detect delirium as early as possible, in order to minimize the detrimental effects of delirium in cognition and behavior. The Lucidify algorithm, different from our previously utilized EEG system (see below for details) can provide two additional features not previously available: (1) accelerometer data (an indicator of the level of patient's movements and a proxy for delirium phenotype; and (2) scored polysomnography data (providing validated interpretation of the patient's spectral sleep - thus a true measure of the patient's various stages and quality of sleep; which has direct implications on both the progression of delirium and the patient's overall health and recovery). Finally, the CGX system is simpler, more comfortable to wear, and better tolerated by medically ill patients.

The primary objective is to monitor the development and progression of delirium (acute confusion) and sleep disturbances associated with medical illness over time. The study will focus on two distinct patient populations: 1) patients admitted to an adult intensive care unit (ICU), and 2) patients in oncology units with hematologic malignancies undergoing cellular therapies or hematopoietic stem cell transplants (e.g., stem cell and Chimeric Antigen Receptor T-cell (CAR-T) Therapy). The rationale for targeting the occurrence of delirium, as its development has been associated with significantly poor hospital care outcomes and increased morbidity (medical complications) and mortality (death). The two patient populations have been specifically selected for the following reasons: Delirium is frequently observed in the ICU setting, with a reported prevalence of up to 85%. In the hematologic malignancies undergoing cellular therapies or hematopoietic stem cell transplants population, there is a significant prevalence of neurotoxicity associated with delirium, ranging from 20% to 60%. This neurotoxicity can lead to comorbid risks such as seizures and cerebral edema, and it is also associated with long-term cognitive impairment and depression (Hayden 2022, Ruark 2020).

In comparison to other portable EEG devices, the CGX EEG system investigators intend to investigate during the course of this specific study is more user-friendly (i.e., smaller, more portable, and has no wirings attaching the patient to the bed or an external device) , allowing for continuous monitoring without patient discomfort or interference associated with other monitoring systems currently used in our ICU setting. In addition to this system's tolerability and simplicity, this new device and AI-algorithm allows for the acquisition of two significant variables not previously available: (a) its algorithm allows for accelerometer data acquisition (this is a measure of the patient's motion, which will constitute an ideal and objective measure of the delirium phenotype (e.g., hypoactive, hyperactive, or mixed delirium subtype); and (b) the system allows for the measurement of the various phases of the sleep cycle, thus providing a full hypnogram of the quality and duration of sleep. Taking advantage of the enhanced comfort of wearing this new system; given the waxing and waning nature of delirium (i.e., how quickly it can vary through the course of 24-hrs) and In order to take full advantage of the system's capabilities, study investigators need the CGX recorder to remain in place 24/7 for the duration of the study.

Inclusion Criteria:

1. Age is 55 years or older
2. Clinical suspicion of delirium or subject at risk for delirium
3. Admitted to the Intensive Care Unit (ICU) or Oncology wards
4. Expected hospital stay is greater than one (1) day
5. Subject must be fluent in English

Exclusion Criteria:

1. Age is younger than 55 years
2. Subjects with a primary neurological or neurosurgical condition such as stroke, epilepsy, brain tumor, or witnessed seizures, Parkinson's disease, traumatic brain injury, or s/p craniectomy
3. Active CNS substance abuse, intoxication, or withdrawal
4. Unarousable or unresponsive subjects with RASS <-3
5. Subject is blind, deaf, or unable to speak or understand English

Subjects admitted to the ICU or Oncology hospital wards