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The AHI System is intended for use by healthcare professionals managing patients 18 years or older who are receiving continuous physiological monitoring with electrocardiography (ECG) in hospitals.

AHI provides a frequently updated binary output over time based on pattern analysis of a lead-II ECG waveform intended to describe a patient's hemodynamic status and indicate if a patient is showing signs of hemodynamic stability or instability. Signs of hemodynamic instability (HI) are defined as hypotension (systolic blood pressure <90 mmHg or mean arterial pressure (MAP) <70 mmHg) combined with tachycardia (heart rate ≥ 100 bpm).

AHI-PI provides the clinician with physiological insight into a patient's likelihood of a future episode of HI. An episode of HI is defined as 10 continuous minutes or more where HI is present.

The goal of this adjunctive monitoring method is to enable identification of patients who are likely to experience a future episode of HI, and to allow clinicians an opportunity to increase vigilance. This device is intended for adjunctive use with other physical vital sign parameters and patient information and is not intended to independently direct therapy.

The AHI System is a multiparameter system designed to meet clinicians' need to identify patient hemodynamic status and predict patient hemodynamic instability episodes using two analytics:

1. Analytic for Hemodynamic Instability (AHI) (as granted in DEN200022): Utilizing data from a single existing lead of a non-invasive electrocardiograph (ECG), AHI analyzes heart rate variability (HRV) and ECG morphology features to rapidly detect signs of hemodynamic stability or instability and categorize each window of data as either "AHI Stable" or "AHI Unstable." Time trending of AHI outputs is also provided.

2. Analytic for Hemodynamic Instability Predictive Indicator (AHI-PI): Utilizing AHI outputs from up to the most recent 30 minutes of ECG data, AHI-PI indicates the likelihood of a future episode of hemodynamic instability, defined as ten continuous minutes or more where signs of hemodynamic instability are present.

Here's a breakdown of the acceptance criteria and the study proving the device meets them, based on the provided text:

1. Table of Acceptance Criteria and Reported Device Performance

2. Sample Size Used for the Test Set and Data Provenance

• Sample Size: 65,969 "windows" (data points representing a period of time for which an AHI-PI indicator was generated). The exact number of patients is not explicitly stated, but the note mentions: "The unit of analysis here is at the windows level and not the patient level." The study used bootstrapping to account for multiple measurements per subject.
• Data Provenance: Prospectively collected from consecutive patients at Michigan Medicine. This indicates the data is from the United States and is prospective.
• Targeted Patient Population: Hospitalized patients 18 years or older who are receiving continuous physiological monitoring with electrocardiography (ECG) and are not contraindicated. Due to study design considerations, the primary study population was limited to patients who were invasively monitored with an arterial line.

3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts

• The document does not mention the use of experts to establish the ground truth for the test set.

4. Adjudication Method for the Test Set

• The document does not mention an adjudication method for the test set.

5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance

• No MRMC comparative effectiveness study is mentioned for the AHI-PI system. The study focuses on the standalone performance of the AHI-PI algorithm. The device is intended for "adjunctive use" meaning it supports human healthcare professionals, but specific studies on human improvement with AI assistance are not described here.

6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was done

• Yes, a standalone performance study was done for the AHI-PI. The reported data in the table directly reflects the algorithm's ability to predict hemodynamic instability without human intervention in the prediction process itself. The study compared AHI-PI outputs to a vital signs reference standard.

7. The Type of Ground Truth Used (expert consensus, pathology, outcomes data, etc.)

• Outcomes Data/Physiological Reference Standard: The ground truth for hemodynamic instability (HI) was defined using a "hemodynamic vital signs reference standard" based on continuous vital signs:
  • Hypotension (systolic blood pressure <90 mmHg or mean arterial pressure (MAP) <70 mmHg) combined with
  • Tachycardia (heart rate ≥ 100 bpm)
• An "episode of HI" was further defined as 10 continuous minutes or more where these HI conditions are present.

8. The Sample Size for the Training Set

• The document does not specify the sample size used for the training set. It only describes the validation data.

9. How the Ground Truth for the Training Set Was Established

• The document does not specify how the ground truth for the training set was established. It only describes the ground truth for the validation set.

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