ng-model inside an ng-repeat

Question

I tested several answers I found here, but nothing solved.

Each dataSample.name generates a line, with a SELECT with other options:

Example:

dataSample

exame sangue  -------  select -> tipo_de_tubo 1 / tipo_de_tubo_2 / tipo_de_tubo3

exame urina  -------  select -> tipo_de_tubo 1 / tipo_de_tubo_2 / tipo_de_tubo3

What happens is, when I select the type of tube from any of the exams, it repeats to all the other Selects.

  <div layout="column" class="mt-20">
    <div layout-gt-xs="row" class="data-row" ng-repeat="dataSample in BioBanco.content.data_sample" ng-model="BioBanco.data">
        <div flex-gt-xs>
          <md-checkbox >
              @{{dataSample.name}}
          </md-checkbox>
        </div>
        
        <div layout-gt-xs>
          <ng-md-icon  icon="opacity"  class="@{{dataSample.slug}}-1"   ng-click="BioBanco.tube(dataSample.slug, 1)" size="24"></ng-md-icon>
          <ng-md-icon  icon="opacity"  class="@{{dataSample.slug}}-2"   ng-click="BioBanco.tube(dataSample.slug, 2)" size="24"></ng-md-icon>
          <ng-md-icon  icon="opacity"  class="@{{dataSample.slug}}-3"   ng-click="BioBanco.tube(dataSample.slug, 3)" size="24"></ng-md-icon>
          <ng-md-icon  icon="opacity"  class="@{{dataSample.slug}}-4"   ng-click="BioBanco.tube(dataSample.slug, 4)" size="24"></ng-md-icon>
          <md-input-container  flex-gt-xs   class="component-render tube-type ">
          <md-tooltip md-direction="top" >Informar Quantidade e Tipo de Tubo</md-tooltip>
            <md-select ng-model="Biobanco.data.tube" aria-label="sexo do paciente"> 
              <md-option value="Citrato">                Citrato</md-option>
              <md-option value="EDTA">                   EDTA</md-option>
              <md-option value="Fluoreto de Sódio">      Fluoreto de Sódio</md-option>
              <md-option value="Heparina">               Heparina</md-option>
              <md-option value="Seco com Gel Reparador"> Seco com Gel Reparador</md-option>
              <md-option value="Sem Conservante">        Sem Conservante</md-option>
              <md-option value="RNA-Later">              RNA-Later</md-option>
              <md-option value="RNA/DNA Reag Estab">     RNA/DNA Reagente Estabilizante</md-option>
              <md-option value="Outros tubos">           Outros</md-option>
            </md-select>
          </md-input-container>
        </div>

        <div layout-gt-xs="row" > 
          <md-input-container  flex-gt-xs class="tube-type after">
          <span class="md-title label">Obs.:</span>
            <input  aria-label="observação" type="text"> 
          </md-input-container>
        </div>
        
    </div>
  </div>