diff --git a/HealthMonitor.WebApi/Worker.cs b/HealthMonitor.WebApi/Worker.cs
index 6e45830..1ae44a3 100644
--- a/HealthMonitor.WebApi/Worker.cs
+++ b/HealthMonitor.WebApi/Worker.cs
@@ -2459,9 +2459,16 @@ namespace HealthMonitor.WebApi
         public async Task CalculateNormalFetalHeartRateIntervalAsync(HisGpsHeartRate heartRate, PregnancyCommonHeartRateModel commonPHR,int highFreqSampleInterval)
         {
             var daysPhr = await _serviceTDengine.GetBySerialNoAsync<PregnancyHeartRateModel>(heartRate.Serialno, 7);
-            var filteredPhr = daysPhr.Where(i => i.LastUpdate >= heartRate.LastUpdate && i.LastUpdate <= DateTime.Now).ToList();
+            var now = DateTime.Now;
+            var filteredPhr = daysPhr.Where(i => i.LastUpdate >= heartRate.LastUpdate && i.LastUpdate <= now).ToList();
             // 去除高频
             var normalPhr = GetNonFreqPregnancyHeartRate(filteredPhr, highFreqSampleInterval).OrderBy(i => i.LastUpdate);
+            
+            if (normalPhr.ToList().Count==0)
+            {
+                _logger.LogWarning($"{heartRate.Serialno} 时间段{heartRate.LastUpdate}-{now},去除高频心率数据后,没有常规数据,不计算常规胎心数据");
+                return;
+            }
 
             var startPhr = normalPhr.First();
             var endPhr = normalPhr.Last();