feature: Sepsis Early Warning Engine

2026-06-17 01:05:15 +08:00
parent fde3d56484
commit ec780144c6
12 changed files with 1194 additions and 8 deletions
@@ -0,0 +1,38 @@
+using StackExchange.Redis;
+
+public static class SirsEvaluator
+{
+    // The four SIRS codes defined by this project's simplified SIRS criteria.
+    // Observations for any other code are ignored by the sepsis engine entirely —
+    // they pass through to the outbox and Elasticsearch but do not affect SIRS state.
+    public static readonly IReadOnlySet<string> SirsCodes =
+        new HashSet<string> { "TEMP_C", "HEART_RATE", "RESP_RATE", "WBC_K_UL" };
+
+    // Returns true if the observation value meets the SIRS criterion for its code.
+    // These thresholds are clinical parameters, not configuration — changing them
+    // requires clinical review, not a config file edit. They live here as named constants.
+    public static bool MeetsCriterion(string observationCode, decimal value) =>
+        observationCode switch
+        {
+            // Fever (> 38.3 °C) or hypothermia (< 36.0 °C)
+            "TEMP_C"     => value > 38.3m || value < 36.0m,
+            // Tachycardia
+            "HEART_RATE" => value > 90m,
+            // Tachypnea
+            "RESP_RATE"  => value > 20m,
+            // Leukocytosis or leukopenia
+            "WBC_K_UL"   => value > 12.0m || value < 4.0m,
+            _             => false
+        };
+
+    // Redis key for one SIRS criterion for one encounter.
+    public static string CriterionKey(Guid encounterId, string code) =>
+        $"sirs:{encounterId}:{code}";
+
+    // All four Redis keys for one encounter — used in MGET to count active criteria.
+    // The order is stable so the MGET result array always maps to the same codes.
+    public static RedisKey[] AllCriterionKeys(Guid encounterId) =>
+        SirsCodes
+            .Select(code => (RedisKey)CriterionKey(encounterId, code))
+            .ToArray();
+}