diff --git a/app/src/main/java/com/medithings/vesiscan/ui/views/monitoring/PiezoMonitoringView.kt b/app/src/main/java/com/medithings/vesiscan/ui/views/monitoring/PiezoMonitoringView.kt
index 2c3fd03..64dae3c 100644
--- a/app/src/main/java/com/medithings/vesiscan/ui/views/monitoring/PiezoMonitoringView.kt
+++ b/app/src/main/java/com/medithings/vesiscan/ui/views/monitoring/PiezoMonitoringView.kt
@@ -643,7 +643,11 @@ fun PiezoMonitoringView(appState: AppState) {
         }
         bleManager.piezoCollector.onLog = { msg -> Log.d("PiezoCollector", msg) }
 
-        if (!bleManager.sendChannelsOnly()) {
+        // 2026-07-07 fix: sendChannelsOnly (maa, 6ch only) → sendMtb (6ch + IMU).
+        //   Auto scan 중 IMU 완전 실종 (line 843 주석 "mtb 응답에 IMU" 는 정확하지만
+        //   실제 코드는 maa 였음 → 회귀 버그). mtb 는 응답에 rim: (IMU 15 sample) 포함,
+        //   imuCollector.onComplete 로 posture 자동 갱신.
+        if (!bleManager.sendMtb()) {
             // Throttle됨 — isMeasuring 리셋 (deadlock 방지)
             isMeasuring = false
             try { measureDoneSignal.value.complete(Unit) } catch (_: Exception) {}
@@ -657,7 +661,7 @@ fun PiezoMonitoringView(appState: AppState) {
                 measureRetryCount++
                 Log.w("PiezoMonitor", "Timeout — auto-retry $measureRetryCount/$maxMeasureRetries")
                 bleManager.piezoCollector.reset()
-                bleManager.sendChannelsOnly()
+                bleManager.sendMtb()
                 // Second timeout for retry
                 handler.postDelayed({
                     if (!isMeasuring) return@postDelayed