Clear buffer scanner Fujitsu Fi-7160 in c#

I'm working on a company Project, C # Windows Form and I'm still a beginner on the dot net platform. I would like to know with friends of profession, if there is any way I can clean the buffer of the Fujitsu Fi-7160 Scanner, after scanning about 1500 sheets, because always the application presents message of lack of memory, full buffer and to be able to re-scan, it is necessary to close and open the application again. Already downloaded, installed and updated all drivers from the manufacturer, though still unsuccessful. I have already sought solutions directly on the manufacturer's website, but without success either. As far as I researched, the application is 32-bit, running on windows 10 64-bit, the scanner uses the hdmi port of the notebook, the application communicates with the scanner through the IP PaperStream program (TWAIN). From now on I thank you, if friends can help me with some guidance.

private string scannearParaArquivo(string arquivo, bool mostraConfig)
    {
        //
        string ret = "";
        AcquireModalState acquireModalState;
        using (DeviceManager deviceManager = new DeviceManager())
        {
            deviceManager.Open();

            Device device = deviceManager.Devices.Current;



            try
            {
                // open the device 
                device.Open();
            }
            catch (Exception ex)
            {
                return string.Concat("Não foi possivel acessar o scanner: ",ex.Message.ToString());
            }

            try
            {
                // set acquisition parameters 


                device.ShowUI = mostraConfig;
                device.DisableAfterAcquire = true;
                device.TransferMode = TransferMode.Memory;
                device.FileFormat = TwainImageFileFormat.Tiff;


                device.AcquiredImages.TiffMultiPage = false;
                device.AcquiredImages.TiffCompression = TiffCompression.Auto;

                device.AcquiredImages.AutoClean = true;
            }
            catch (Exception ex)
            {
                return string.Concat("Erro na configuração do Scanner: ", ex.Message.ToString());
            }


            // set filename the first acquired image
            imageIndex++;
            device.FileName = string.Concat(arquivo, imageIndex.ToString("00000000"), ".tif");

            bool atingiuMaximoDocto = false;

            // acquire images from device 
            acquireModalState = AcquireModalState.None;
            do
            {
                int ponto = 0;
                try
                {
                    acquireModalState = device.AcquireModal();
                    switch (acquireModalState)
                    {
                        case AcquireModalState.ImageAcquired:
                            //
                            ponto = 1;
                            string i = device.FileName;
                            device.AcquiredImages.Last.Save(i);
                            mostraCaptura(imageIndex, i);
                            //set filename for next acquired image 
                            imageIndex++;
                            device.FileName = string.Concat(arquivo, imageIndex.ToString("00000000"), ".tif");
                            GC.Collect(); // 10/07/2018
                            break;
                        case AcquireModalState.ScanCompleted:
                            // Fim de captura saida normal
                            // close the device 
                            ponto = 2;
                            device.Dispose();
                            device.Close();
                            // close the device manager 
                            device.AcquiredImages.Clear();
                            deviceManager.Dispose();
                            deviceManager.Close();
                            GC.Collect(); // 10/07/2018
                            break;
                        case AcquireModalState.ScanCanceled:
                            // Fim da captura por atingir maximo de documento ou por cancelamento
                            ponto = 3;
                            if (atingiuMaximoDocto == true)
                            {
                                MessageBox.Show("Quantidade de documentos digitalizados ultrapassou o limite. \n Feche este lote e inicie um novo Lote. \n\n Atenção, verifique os ultimos documento digitalizado.\n\n\n Digitalização encerrada, confira os ultimos documentos", "Aviso do Sistema", MessageBoxButtons.OK, MessageBoxIcon.Error);
                            }
                            // close the device 
                            device.Dispose();
                            device.Close();
                            // close the device manager 
                            deviceManager.Dispose();
                            deviceManager.Close();
                            GC.Collect(); // 10/07/2018
                            break;
                        case AcquireModalState.ScanFailed:
                            // close the device 
                            ponto = 4;
                            device.Dispose();
                            device.Close();
                            // close the device manager 
                            deviceManager.Dispose();
                            deviceManager.Close();
                            GC.Collect(); // 10/07/2018
                            ret = "Verifique se há documento";
                            break;
                    }
                    if (imageIndex > 111 & atingiuMaximoDocto == false)
                    {
                        if (device != null)
                        {
                            // send command to cancel the transfer  
                            if (device.State == DeviceState.Transferring || device.State == DeviceState.TransferReady)
                            {
                                ponto = 5;
                                device.CancelTransfer();
                            }
                        }
                        atingiuMaximoDocto = true;
                    }
                }
                catch (Exception ex)
                {
                    // Erro inesperado na Captura
                    ret = ex.Message.ToString();
                    LogSistema.logProcessamento(string.Concat("Erro inesperado na captura no ponto ", ponto.ToString()), pathLog);
                    LogSistema.logProcessamento(string.Concat("Pasta ", arquivo, " - " , this.labNumeroEquipamento.Text), pathLog);
                    LogSistema.logProcessamento(ret, pathLog);
                    LogSistema.logProcessamento("======================================================================", pathLog);
                }

            }
            while (acquireModalState != AcquireModalState.None);
            imageIndex--;
            return ret;
        }
    }