diff --git a/lims_management/models/lims_result.py b/lims_management/models/lims_result.py
index 9e2da51..b4a885f 100644
--- a/lims_management/models/lims_result.py
+++ b/lims_management/models/lims_result.py
@@ -92,17 +92,10 @@ class LimsResult(models.Model):
         string='Valor de Texto'
     )
     
-    # Keep as Char but add domain validation
     value_selection = fields.Char(
         string='Valor de Selección'
     )
     
-    # Add Selection field with dynamic options
-    value_selection_field = fields.Selection(
-        selection='_get_selection_options',
-        string='Valor de Selección'
-    )
-    
     # Campo para mostrar las opciones disponibles
     selection_options_display = fields.Char(
         string='Opciones disponibles',
@@ -321,7 +314,6 @@ class LimsResult(models.Model):
             self.value_numeric = False
             self.value_text = False
             self.value_selection = False
-            self.value_selection_field = False
             self.value_boolean = False
             
             # Si es selección, obtener las opciones
@@ -329,19 +321,6 @@ class LimsResult(models.Model):
                 # Esto se usará en las vistas para mostrar las opciones dinámicamente
                 pass
     
-    @api.onchange('value_selection_field')
-    def _onchange_value_selection_field(self):
-        """Sincroniza el campo de selección con el campo char."""
-        if self.parameter_value_type == 'selection':
-            self.value_selection = self.value_selection_field
-    
-    def _get_selection_options(self):
-        """Retorna las opciones de selección basadas en el parámetro."""
-        options = []
-        if self.parameter_id and self.parameter_value_type == 'selection':
-            param_options = self.parameter_id.get_selection_list()
-            options = [(opt, opt) for opt in param_options]
-        return options or [('', 'Sin opciones')]
     
     @api.depends('parameter_id', 'parameter_id.selection_values')
     def _compute_selection_options_display(self):
diff --git a/lims_management/views/lims_test_views.xml b/lims_management/views/lims_test_views.xml
index 1986aea..609dbff 100644
--- a/lims_management/views/lims_test_views.xml
+++ b/lims_management/views/lims_test_views.xml
@@ -88,16 +88,18 @@
                                         <field name="value_text" 
                                                invisible="parameter_value_type != 'text'"
                                                class="oe_edit_only"/>
+                                        <field name="parameter_id" invisible="1" force_save="1"/>
                                         <field name="value_selection" 
                                                invisible="parameter_value_type != 'selection'"
-                                               placeholder="Escriba para buscar..."
-                                               class="oe_edit_only"/>
+                                               placeholder="Seleccione una opción"
+                                               options="{'no_create': True, 'no_edit': True}"/>
                                         <field name="selection_options_display"
                                                invisible="parameter_value_type != 'selection'"
                                                readonly="1"
                                                nolabel="1"
                                                class="text-muted small"
-                                               style="font-size: 0.85em; color: #6c757d;"/>
+                                               widget="text"
+                                               style="font-size: 0.85em; color: #6c757d; margin-top: -5px;"/>
                                         <field name="value_boolean" 
                                                invisible="parameter_value_type != 'boolean'"
                                                widget="boolean_toggle"
diff --git a/test/check_selection_issue.py b/test/check_selection_issue.py
new file mode 100644
index 0000000..41ba329
--- /dev/null
+++ b/test/check_selection_issue.py
@@ -0,0 +1,101 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+"""
+Script para diagnosticar por qué el selection muestra "Sin Opciones"
+"""
+
+import odoo
+import logging
+
+_logger = logging.getLogger(__name__)
+
+
+def check_selection_issue(env):
+    """Verificar el problema con las opciones de selección"""
+    
+    print("=" * 80)
+    print("DIAGNÓSTICO DE PROBLEMA CON SELECTION")
+    print("=" * 80)
+    
+    # Buscar el resultado específico mencionado por el usuario
+    result = env['lims.result'].browse(43)
+    if not result.exists():
+        print("No se encontró el resultado con ID 43")
+        # Buscar cualquier resultado de tipo selection
+        result = env['lims.result'].search([
+            ('parameter_value_type', '=', 'selection')
+        ], limit=1)
+    
+    if result:
+        print(f"\nResultado encontrado:")
+        print(f"  - ID: {result.id}")
+        print(f"  - Parámetro: {result.parameter_id.name}")
+        print(f"  - Tipo de valor: {result.parameter_value_type}")
+        print(f"  - Valor actual: '{result.value_selection}'")
+        
+        # Verificar el parámetro
+        param = result.parameter_id
+        print(f"\nInformación del parámetro:")
+        print(f"  - ID: {param.id}")
+        print(f"  - Nombre: {param.name}")
+        print(f"  - Tipo de valor: {param.value_type}")
+        print(f"  - Valores de selección (campo): '{param.selection_values}'")
+        
+        # Probar get_selection_list()
+        print(f"\nProbando get_selection_list():")
+        selection_list = param.get_selection_list()
+        print(f"  - Resultado: {selection_list}")
+        print(f"  - Tipo: {type(selection_list)}")
+        print(f"  - Longitud: {len(selection_list) if selection_list else 0}")
+        
+        # Probar _get_selection_options() en el resultado
+        print(f"\nProbando _get_selection_options() en el resultado:")
+        options = result._get_selection_options()
+        print(f"  - Opciones: {options}")
+        
+        # Verificar si el método está siendo llamado correctamente
+        print(f"\nVerificando contexto:")
+        print(f"  - result.parameter_id existe: {bool(result.parameter_id)}")
+        print(f"  - result.parameter_value_type: '{result.parameter_value_type}'")
+        print(f"  - Condición completa: {result.parameter_id and result.parameter_value_type == 'selection'}")
+        
+        # Buscar todos los parámetros de tipo selection
+        print(f"\n\nBuscando todos los parámetros de tipo selection:")
+        selection_params = env['lims.analysis.parameter'].search([
+            ('value_type', '=', 'selection')
+        ])
+        
+        for sp in selection_params:
+            print(f"\n  Parámetro: {sp.name}")
+            print(f"    - selection_values: '{sp.selection_values}'")
+            print(f"    - get_selection_list(): {sp.get_selection_list()}")
+    
+    else:
+        print("No se encontraron resultados de tipo selection")
+
+
+if __name__ == '__main__':
+    # Configuración
+    db_name = 'lims_demo'
+    
+    # Conectar a Odoo
+    odoo.tools.config.parse_config(['--database', db_name])
+    
+    # Obtener el registro de la base de datos
+    registry = odoo.registry(db_name)
+    
+    # Crear cursor y environment
+    with registry.cursor() as cr:
+        env = odoo.api.Environment(cr, odoo.SUPERUSER_ID, {})
+        
+        try:
+            # Verificar el problema
+            check_selection_issue(env)
+            
+            # No guardar cambios
+            cr.rollback()
+            
+        except Exception as e:
+            cr.rollback()
+            print(f"\n❌ Error durante el diagnóstico: {str(e)}")
+            _logger.error(f"Error: {str(e)}", exc_info=True)
\ No newline at end of file
diff --git a/test/create_test_selection_data.py b/test/create_test_selection_data.py
new file mode 100644
index 0000000..ecebb3f
--- /dev/null
+++ b/test/create_test_selection_data.py
@@ -0,0 +1,132 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+"""
+Script para crear datos de prueba con parámetros de tipo selection
+"""
+
+import odoo
+import logging
+
+_logger = logging.getLogger(__name__)
+
+
+def create_test_selection_data(env):
+    """Crear datos de prueba para verificar el widget selection"""
+    
+    print("=" * 80)
+    print("CREANDO DATOS DE PRUEBA PARA SELECTION")
+    print("=" * 80)
+    
+    # Buscar o crear paciente
+    patient = env['res.partner'].search([('is_patient', '=', True)], limit=1)
+    if not patient:
+        patient = env['res.partner'].create({
+            'name': 'Paciente Test Selection Widget',
+            'is_patient': True,
+        })
+        print(f"Paciente creado: {patient.name}")
+    
+    # Buscar análisis con parámetros tipo selection
+    # Por ejemplo: Prueba de Embarazo
+    product = env['product.template'].search([
+        ('is_analysis', '=', True),
+        ('name', 'ilike', 'embarazo')
+    ], limit=1)
+    
+    if product:
+        print(f"\nAnálisis encontrado: {product.name}")
+        
+        # Verificar parámetros asociados
+        print("\nParámetros del análisis:")
+        for param_link in product.parameter_ids:
+            param = param_link.parameter_id
+            print(f"  - {param.name} (Tipo: {param.value_type})")
+            if param.value_type == 'selection':
+                print(f"    Valores: '{param.selection_values}'")
+                print(f"    Lista: {param.get_selection_list()}")
+    else:
+        print("No se encontró análisis de Prueba de Embarazo")
+        
+        # Buscar cualquier análisis con parámetros selection
+        sql = """
+        SELECT DISTINCT pt.id, pt.name
+        FROM product_template pt
+        JOIN product_template_parameter ptp ON ptp.product_template_id = pt.id
+        JOIN lims_analysis_parameter lap ON lap.id = ptp.parameter_id
+        WHERE pt.is_analysis = true
+        AND lap.value_type = 'selection'
+        LIMIT 5
+        """
+        env.cr.execute(sql)
+        results = env.cr.fetchall()
+        
+        if results:
+            print("\nAnálisis con parámetros selection encontrados:")
+            for prod_id, prod_name in results:
+                print(f"  - {prod_name} (ID: {prod_id})")
+                product = env['product.template'].browse(prod_id)
+                break
+        else:
+            print("No se encontraron análisis con parámetros selection")
+            return
+    
+    # Crear orden
+    order = env['sale.order'].create({
+        'partner_id': patient.id,
+        'is_lab_request': True,
+        'order_line': [(0, 0, {
+            'product_id': product.product_variant_id.id,
+            'product_uom_qty': 1,
+        })]
+    })
+    
+    # Confirmar orden
+    order.action_confirm()
+    print(f"\nOrden creada: {order.name}")
+    
+    # Obtener la prueba generada
+    if order.lab_test_ids:
+        test = order.lab_test_ids[0]
+        print(f"Prueba generada: {test.name} (ID: {test.id})")
+        
+        # Generar resultados si no existen
+        if not test.result_ids:
+            test.sudo()._generate_test_results()
+        
+        print(f"\nResultados generados:")
+        for result in test.result_ids:
+            print(f"  - {result.parameter_id.name} (Tipo: {result.parameter_value_type})")
+            if result.parameter_value_type == 'selection':
+                print(f"    ID del resultado: {result.id}")
+                print(f"    Valores en parámetro: '{result.parameter_id.selection_values}'")
+                print(f"    get_selection_list(): {result.parameter_id.get_selection_list()}")
+                print(f"    _get_selection_options(): {result._get_selection_options()}")
+                print(f"    selection_options_display: '{result.selection_options_display}'")
+    
+    # Guardar cambios
+    env.cr.commit()
+    print("\n✅ Datos de prueba creados exitosamente")
+    
+
+if __name__ == '__main__':
+    # Configuración
+    db_name = 'lims_demo'
+    
+    # Conectar a Odoo
+    odoo.tools.config.parse_config(['--database', db_name])
+    
+    # Obtener el registro de la base de datos
+    registry = odoo.registry(db_name)
+    
+    # Crear cursor y environment
+    with registry.cursor() as cr:
+        env = odoo.api.Environment(cr, odoo.SUPERUSER_ID, {})
+        
+        try:
+            # Crear datos de prueba
+            create_test_selection_data(env)
+            
+        except Exception as e:
+            cr.rollback()
+            print(f"\n❌ Error: {str(e)}")
+            _logger.error(f"Error: {str(e)}", exc_info=True)
\ No newline at end of file
diff --git a/test/verify_selection_fix.py b/test/verify_selection_fix.py
new file mode 100644
index 0000000..a1149d6
--- /dev/null
+++ b/test/verify_selection_fix.py
@@ -0,0 +1,100 @@
+import odoo
+import json
+
+def verify_selection_fix(cr):
+    """Verify that the selection widget fix is working correctly."""
+    env = odoo.api.Environment(cr, odoo.SUPERUSER_ID, {})
+    
+    print("="*80)
+    print("VERIFYING SELECTION WIDGET FIX")
+    print("="*80)
+    
+    # 1. Find a parameter with selection type
+    param = env['lims.analysis.parameter'].search([
+        ('value_type', '=', 'selection'),
+        ('selection_values', '!=', False)
+    ], limit=1)
+    
+    if not param:
+        print("ERROR: No selection parameters found!")
+        return
+    
+    print(f"\nUsing parameter: {param.name} (ID: {param.id})")
+    print(f"Selection values: {param.selection_values}")
+    print(f"get_selection_list(): {param.get_selection_list()}")
+    
+    # 2. Create a test and result
+    print("\n\nCreating test data...")
+    
+    # Get a patient
+    patient = env['res.partner'].search([('is_patient', '=', True)], limit=1)
+    if not patient:
+        print("ERROR: No patient found!")
+        return
+    
+    # Create a test
+    test = env['lims.test'].create({
+        'name': 'Test Selection Widget',
+        'patient_id': patient.id,
+        'analysis_id': param.analysis_id.id if param.analysis_id else False,
+    })
+    print(f"Created test: {test.name} (ID: {test.id})")
+    
+    # Create a result
+    result = env['lims.result'].create({
+        'test_id': test.id,
+        'parameter_id': param.id,
+    })
+    print(f"Created result: ID {result.id}")
+    
+    # 3. Check the selection field
+    print("\n\nChecking selection field...")
+    print(f"Parameter value type: {result.parameter_value_type}")
+    print(f"Selection options display: {result.selection_options_display}")
+    
+    # Get selection options through the method
+    options = result._get_selection_options()
+    print(f"\n_get_selection_options() returns: {options}")
+    
+    # 4. Test setting a value
+    if options and len(options) > 1:  # Skip the empty option
+        test_value = options[1][0]  # Get the key of the first real option
+        print(f"\nTesting with value: '{test_value}'")
+        
+        result.value_selection_field = test_value
+        print(f"Set value_selection_field = '{test_value}'")
+        print(f"After onchange, value_selection = '{result.value_selection}'")
+        print(f"Value display: '{result.value_display}'")
+        
+        # Save and check
+        cr.commit()
+        
+        # Re-read
+        result = env['lims.result'].browse(result.id)
+        print(f"\nAfter save and re-read:")
+        print(f"  value_selection_field: '{result.value_selection_field}'")
+        print(f"  value_selection: '{result.value_selection}'")
+        print(f"  value_display: '{result.value_display}'")
+    
+    # 5. Check field definition
+    print("\n\nChecking field definitions...")
+    Result = env['lims.result']
+    
+    if 'value_selection_field' in Result._fields:
+        field = Result._fields['value_selection_field']
+        print(f"value_selection_field:")
+        print(f"  Type: {field.type}")
+        print(f"  String: {field.string}")
+        print(f"  Selection: {field.selection if hasattr(field, 'selection') else 'N/A'}")
+    else:
+        print("ERROR: value_selection_field not found in model!")
+    
+    print("\n" + "="*80)
+    print("VERIFICATION COMPLETE")
+    print("="*80)
+
+if __name__ == '__main__':
+    db_name = 'lims_demo'
+    registry = odoo.registry(db_name)
+    with registry.cursor() as cr:
+        verify_selection_fix(cr)
\ No newline at end of file