diff --git a/app/Models/Enums/PatientSex.php b/app/Models/Enums/PatientSex.php
new file mode 100644
index 0000000..08aedea
--- /dev/null
+++ b/app/Models/Enums/PatientSex.php
@@ -0,0 +1,10 @@
+<?php
+
+namespace App\Models\Enums;
+
+enum PatientSex: string
+{
+    case Female = 'F';
+    case Male = 'M';
+    case Other = 'O';
+}
diff --git a/database/migrations/2024_12_27_060234_create_studies_table.php b/database/migrations/2024_12_27_060234_create_studies_table.php
index 3bd832c..61e93ff 100644
--- a/database/migrations/2024_12_27_060234_create_studies_table.php
+++ b/database/migrations/2024_12_27_060234_create_studies_table.php
@@ -19,7 +19,7 @@ public function up(): void
             $table->boolean('is_locked')->default(false);
             $table->unsignedTinyInteger('study_priority')->default(0);
             $table->string('patient_id')->nullable();
-            $table->string('patient_uid')->nullable();
+            $table->string('patient_uuid')->nullable()->index();
             $table->string('patient_name');
             $table->string('patient_sex')->nullable();
             $table->date('patient_birthdate')->nullable();
@@ -52,7 +52,7 @@ public function up(): void
             $table->timestamps();
 
             $table->index(['referring_physician_id', 'receive_date']);
-            $table->index(['institute_id', 'receive_date']);
+            $table->index(['institute_id', 'receive_date', 'is_archived']);
             $table->index(['institute_id', 'report_status', 'study_priority', 'receive_date']);
             $table->index(['assigned_physician_id', 'report_status', 'study_priority', 'receive_date']);
         });
diff --git a/database/migrations/2024_12_28_144858_create_study_details_table.php b/database/migrations/2024_12_28_144858_create_study_details_table.php
index f2bbb25..73197ad 100644
--- a/database/migrations/2024_12_28_144858_create_study_details_table.php
+++ b/database/migrations/2024_12_28_144858_create_study_details_table.php
@@ -16,8 +16,8 @@ public function up(): void
             $table->text('surgical_history')->nullable();
             $table->text('lab_results')->nullable();
             $table->text('clinical_diagnosis')->nullable();
-            $table->json('properties')->nullable();
-            $table->json('series')->nullable();
+            $table->jsonb('properties')->nullable();
+            $table->jsonb('series')->nullable();
             $table->timestamps();
         });
     }