diff --git a/app/src/main/java/com/example/medilightv2android/ui/views/monitoring/PiezoMonitoringView.kt b/app/src/main/java/com/example/medilightv2android/ui/views/monitoring/PiezoMonitoringView.kt
index 934d511..1829534 100644
--- a/app/src/main/java/com/example/medilightv2android/ui/views/monitoring/PiezoMonitoringView.kt
+++ b/app/src/main/java/com/example/medilightv2android/ui/views/monitoring/PiezoMonitoringView.kt
@@ -123,6 +123,15 @@ fun PiezoMonitoringView(appState: AppState) {
                 lastMultiChannelResult.clear()
                 lastMultiChannelResult.addAll(channels)
 
+                // Detachment 체크
+                val sortedBuffers = channels.sortedBy { it.channel }.map { it.buffer }
+                val detachResult = com.example.medilightv2android.managers.DetachmentDetection.detect(sortedBuffers)
+                if (detachResult.isDetached) {
+                    Log.w("PiezoMonitor", "DETACHED mean=${"%.1f".format(detachResult.meanAbs)} std=${"%.1f".format(detachResult.stdVal)}")
+                    bleManager.debugLogger.warn("DETACHED mean=${"%.1f".format(detachResult.meanAbs)} std=${"%.1f".format(detachResult.stdVal)}")
+                    handler.post { bleManager.sendLedMode(4) }
+                }
+
                 var rawVolumeMl: Double? = null
                 var rawLrRatio = 1.0
                 var totalWallCount = 0
diff --git a/app/src/main/java/com/example/medilightv2android/ui/views/monitoring/PlacementGuideView.kt b/app/src/main/java/com/example/medilightv2android/ui/views/monitoring/PlacementGuideView.kt
index 7866793..d49082a 100644
--- a/app/src/main/java/com/example/medilightv2android/ui/views/monitoring/PlacementGuideView.kt
+++ b/app/src/main/java/com/example/medilightv2android/ui/views/monitoring/PlacementGuideView.kt
@@ -72,6 +72,7 @@ fun PlacementGuideView(appState: AppState) {
     var lastGuidePhase by remember { mutableStateOf(PlacementPhase.VERTICAL) }
     var lastHintChangeMs by remember { mutableStateOf(0L) }
     var showPlacementSettings by remember { mutableStateOf(false) }
+    var lastLedMode by remember { mutableIntStateOf(-1) }
 
     // 2단계 순차 탐색: VERTICAL → LATERAL → GREEN
     var placementPhase by remember { mutableStateOf(PlacementPhase.VERTICAL) }
@@ -234,33 +235,33 @@ fun PlacementGuideView(appState: AppState) {
                     // ── 방향 화살표 ──
                     if (!greenZone) {
                         val arrowColor = Color(0xFFFF9800)
-                        val arrowLen = 40f
-                        val arrowHead = 12f
+                        val arrowLen = 60f
+                        val arrowHead = 18f
 
                         when {
                             directionIcon.contains("up") -> {
                                 val ax = cx; val ay = sensorY - 20f
-                                drawLine(arrowColor, Offset(ax, ay + arrowLen), Offset(ax, ay), strokeWidth = 4f)
-                                drawLine(arrowColor, Offset(ax - arrowHead, ay + arrowHead), Offset(ax, ay), strokeWidth = 4f)
-                                drawLine(arrowColor, Offset(ax + arrowHead, ay + arrowHead), Offset(ax, ay), strokeWidth = 4f)
+                                drawLine(arrowColor, Offset(ax, ay + arrowLen), Offset(ax, ay), strokeWidth = 5f)
+                                drawLine(arrowColor, Offset(ax - arrowHead, ay + arrowHead), Offset(ax, ay), strokeWidth = 5f)
+                                drawLine(arrowColor, Offset(ax + arrowHead, ay + arrowHead), Offset(ax, ay), strokeWidth = 5f)
                             }
                             directionIcon.contains("down") -> {
                                 val ax = cx; val ay = sensorY + sensorH + 20f
-                                drawLine(arrowColor, Offset(ax, ay - arrowLen), Offset(ax, ay), strokeWidth = 4f)
-                                drawLine(arrowColor, Offset(ax - arrowHead, ay - arrowHead), Offset(ax, ay), strokeWidth = 4f)
-                                drawLine(arrowColor, Offset(ax + arrowHead, ay - arrowHead), Offset(ax, ay), strokeWidth = 4f)
+                                drawLine(arrowColor, Offset(ax, ay - arrowLen), Offset(ax, ay), strokeWidth = 5f)
+                                drawLine(arrowColor, Offset(ax - arrowHead, ay - arrowHead), Offset(ax, ay), strokeWidth = 5f)
+                                drawLine(arrowColor, Offset(ax + arrowHead, ay - arrowHead), Offset(ax, ay), strokeWidth = 5f)
                             }
                             directionIcon.contains("left") -> {
                                 val ax = cx - sensorW / 2 - 25f; val ay = sensorY + sensorH / 2
-                                drawLine(arrowColor, Offset(ax + arrowLen, ay), Offset(ax, ay), strokeWidth = 4f)
-                                drawLine(arrowColor, Offset(ax + arrowHead, ay - arrowHead), Offset(ax, ay), strokeWidth = 4f)
-                                drawLine(arrowColor, Offset(ax + arrowHead, ay + arrowHead), Offset(ax, ay), strokeWidth = 4f)
+                                drawLine(arrowColor, Offset(ax + arrowLen, ay), Offset(ax, ay), strokeWidth = 5f)
+                                drawLine(arrowColor, Offset(ax + arrowHead, ay - arrowHead), Offset(ax, ay), strokeWidth = 5f)
+                                drawLine(arrowColor, Offset(ax + arrowHead, ay + arrowHead), Offset(ax, ay), strokeWidth = 5f)
                             }
                             directionIcon.contains("right") -> {
                                 val ax = cx + sensorW / 2 + 25f; val ay = sensorY + sensorH / 2
-                                drawLine(arrowColor, Offset(ax - arrowLen, ay), Offset(ax, ay), strokeWidth = 4f)
-                                drawLine(arrowColor, Offset(ax - arrowHead, ay - arrowHead), Offset(ax, ay), strokeWidth = 4f)
-                                drawLine(arrowColor, Offset(ax - arrowHead, ay + arrowHead), Offset(ax, ay), strokeWidth = 4f)
+                                drawLine(arrowColor, Offset(ax - arrowLen, ay), Offset(ax, ay), strokeWidth = 5f)
+                                drawLine(arrowColor, Offset(ax - arrowHead, ay - arrowHead), Offset(ax, ay), strokeWidth = 5f)
+                                drawLine(arrowColor, Offset(ax - arrowHead, ay + arrowHead), Offset(ax, ay), strokeWidth = 5f)
                             }
                         }
                     }
@@ -534,11 +535,11 @@ fun PlacementGuideView(appState: AppState) {
 
                         if (guideResult.isPass) {
                             isLocked = true
-                            bleManager.sendLedMode(6) // ALIGN_COMPLETE
+                            if (lastLedMode != 6) { bleManager.sendLedMode(6); lastLedMode = 6 }
                             bleManager.debugLogger.info("PLACEMENT_GREEN cv=${"%.3f".format(guideResult.cv)} lr_dev=${"%.3f".format(guideResult.lrDev)} score=${guideResult.score} otsu=${"%.0f".format(analyzer.lastOtsuThreshold)}")
                         } else {
                             isLocked = false
-                            bleManager.sendLedMode(5) // ALIGN_SEARCHING
+                            if (lastLedMode != 5) { bleManager.sendLedMode(5); lastLedMode = 5 }
                             bleManager.debugLogger.info("PLACEMENT_${guideResult.phase.name} score=${guideResult.score} otsu=${"%.0f".format(analyzer.lastOtsuThreshold)} hint=${guideResult.hint}")
                         }
                     }
@@ -798,27 +799,27 @@ private fun SensorLayoutCanvas(
                 when {
                     directionIcon.contains("up") -> {
                         val ax = cx; val ay = cy - 190f
-                        drawLine(orangeColor, Offset(ax, ay + al), Offset(ax, ay), strokeWidth = 4f)
-                        drawLine(orangeColor, Offset(ax - 14f, ay + 14f), Offset(ax, ay), strokeWidth = 4f)
-                        drawLine(orangeColor, Offset(ax + 14f, ay + 14f), Offset(ax, ay), strokeWidth = 4f)
+                        drawLine(orangeColor, Offset(ax, ay + al), Offset(ax, ay), strokeWidth = 5f)
+                        drawLine(orangeColor, Offset(ax - 14f, ay + 14f), Offset(ax, ay), strokeWidth = 5f)
+                        drawLine(orangeColor, Offset(ax + 14f, ay + 14f), Offset(ax, ay), strokeWidth = 5f)
                     }
                     directionIcon.contains("down") -> {
                         val ax = cx; val ay = cy + 190f
-                        drawLine(orangeColor, Offset(ax, ay - al), Offset(ax, ay), strokeWidth = 4f)
-                        drawLine(orangeColor, Offset(ax - 14f, ay - 14f), Offset(ax, ay), strokeWidth = 4f)
-                        drawLine(orangeColor, Offset(ax + 14f, ay - 14f), Offset(ax, ay), strokeWidth = 4f)
+                        drawLine(orangeColor, Offset(ax, ay - al), Offset(ax, ay), strokeWidth = 5f)
+                        drawLine(orangeColor, Offset(ax - 14f, ay - 14f), Offset(ax, ay), strokeWidth = 5f)
+                        drawLine(orangeColor, Offset(ax + 14f, ay - 14f), Offset(ax, ay), strokeWidth = 5f)
                     }
                     directionIcon.contains("left") -> {
                         val ax = cx - 190f; val ay = cy
-                        drawLine(orangeColor, Offset(ax + al, ay), Offset(ax, ay), strokeWidth = 4f)
-                        drawLine(orangeColor, Offset(ax + 14f, ay - 14f), Offset(ax, ay), strokeWidth = 4f)
-                        drawLine(orangeColor, Offset(ax + 14f, ay + 14f), Offset(ax, ay), strokeWidth = 4f)
+                        drawLine(orangeColor, Offset(ax + al, ay), Offset(ax, ay), strokeWidth = 5f)
+                        drawLine(orangeColor, Offset(ax + 14f, ay - 14f), Offset(ax, ay), strokeWidth = 5f)
+                        drawLine(orangeColor, Offset(ax + 14f, ay + 14f), Offset(ax, ay), strokeWidth = 5f)
                     }
                     directionIcon.contains("right") -> {
                         val ax = cx + 190f; val ay = cy
-                        drawLine(orangeColor, Offset(ax - al, ay), Offset(ax, ay), strokeWidth = 4f)
-                        drawLine(orangeColor, Offset(ax - 14f, ay - 14f), Offset(ax, ay), strokeWidth = 4f)
-                        drawLine(orangeColor, Offset(ax - 14f, ay + 14f), Offset(ax, ay), strokeWidth = 4f)
+                        drawLine(orangeColor, Offset(ax - al, ay), Offset(ax, ay), strokeWidth = 5f)
+                        drawLine(orangeColor, Offset(ax - 14f, ay - 14f), Offset(ax, ay), strokeWidth = 5f)
+                        drawLine(orangeColor, Offset(ax - 14f, ay + 14f), Offset(ax, ay), strokeWidth = 5f)
                     }
                 }
             }