diff --git a/src/isolator/hei_isolator.cpp b/src/isolator/hei_isolator.cpp
index 327da54..dc4d09b 100644
--- a/src/isolator/hei_isolator.cpp
+++ b/src/isolator/hei_isolator.cpp
@@ -1,4 +1,5 @@
 
+#include <hei_includes.hpp>
 #include <isolator/hei_isolation_node.hpp>
 #include <isolator/hei_isolator.hpp>
 #include <register/hei_hardware_register.hpp>
@@ -13,6 +14,27 @@
 namespace libhei
 {
 
+//------------------------------------------------------------------------------
+
+// Definitions for the interfaces defined in hei_main.hpp.
+
+void initialize(void* i_buffer, size_t i_bufferSize)
+{
+    Isolator::getSingleton().initialize(i_buffer, i_bufferSize);
+}
+
+void uninitialize()
+{
+    Isolator::getSingleton().uninitialize();
+}
+
+void isolate(const std::vector<Chip>& i_chipList, IsolationData& o_isoData)
+{
+    Isolator::getSingleton().isolate(i_chipList, o_isoData);
+}
+
+//------------------------------------------------------------------------------
+
 void Isolator::initialize(void* i_buffer, size_t i_bufferSize)
 {
     // TODO
diff --git a/src/isolator/hei_signature.hpp b/src/isolator/hei_signature.hpp
deleted file mode 100644
index 2bf91e1..0000000
--- a/src/isolator/hei_signature.hpp
+++ /dev/null
@@ -1,128 +0,0 @@
-#pragma once
-
-#include <hei_includes.hpp>
-
-namespace libhei
-{
-
-/**
- * @brief A signature represents an active attention from a single bit on a
- *        register within a chip.
- *
- * The isolator will gather a list of all active attentions on a chip and return
- * a list of signatures to the user application. The user application should be
- * able to determine what actions to take based on these signatures.
- */
-class Signature
-{
-  public: // Constructors, destructor, assignment, etc.
-    /**
-     * @brief Constructor from components.
-     * @param i_chip     The chip containing this register.
-     * @param i_id       The register ID.
-     * @param i_instance The instance of this register.
-     * @param i_bit      The target bit within this register.
-     * @param i_attnType The attention type reported by this bit.
-     */
-    Signature(const Chip& i_chip, RegisterId_t i_id,
-              RegisterInstance_t i_instance, RegisterBit_t i_bit,
-              AttentionType_t i_attnType) :
-        iv_chip(i_chip),
-        iv_id(i_id), iv_instance(i_instance), iv_bit(i_bit),
-        iv_attnType(i_attnType)
-    {}
-
-    /** @brief Destructor. */
-    ~Signature() = default;
-
-    /** @brief Copy constructor. */
-    Signature(const Signature&) = default;
-
-    /** @brief Assignment operator. */
-    Signature& operator=(const Signature&) = default;
-
-  private:
-    Chip iv_chip;                   ///< Chip containing this register.
-    RegisterId_t iv_id;             ///< Register ID.
-    RegisterInstance_t iv_instance; ///< Instance of this register.
-    RegisterBit_t iv_bit;           ///< Target bit within this register.
-    AttentionType_t iv_attnType;    ///< Attention type reported by this bit.
-
-  public: // Member functions
-    /** @return The chip containing this register. */
-    const Chip& getChip() const
-    {
-        return iv_chip;
-    }
-
-    /** @return The register ID. */
-    RegisterId_t getId() const
-    {
-        return iv_id;
-    }
-
-    /** @return The instance of this register. */
-    RegisterInstance_t getInstance() const
-    {
-        return iv_instance;
-    }
-
-    /** @return The target bit within this register. */
-    RegisterBit_t getBit() const
-    {
-        return iv_bit;
-    }
-
-    /** @return The attention type reported by this bit. */
-    AttentionType_t getAttnType() const
-    {
-        return iv_attnType;
-    }
-
-  public: // Operators
-    /** @brief Equals operator. */
-    bool operator==(const Signature& i_r) const
-    {
-        return (getChip() == i_r.getChip() && getId() == i_r.getId() &&
-                getInstance() == i_r.getInstance() &&
-                getBit() == i_r.getBit() && getAttnType() == i_r.getAttnType());
-    }
-
-    /** @brief Less than operator. */
-    bool operator<(const Signature& i_r) const
-    {
-        if (getChip() < i_r.getChip())
-        {
-            return true;
-        }
-        else if (getChip() == i_r.getChip())
-        {
-            if (getId() < i_r.getId())
-            {
-                return true;
-            }
-            else if (getId() == i_r.getId())
-            {
-                if (getInstance() < i_r.getInstance())
-                {
-                    return true;
-                }
-                else if (getInstance() == i_r.getInstance())
-                {
-                    if (getBit() < i_r.getBit())
-                    {
-                        return true;
-                    }
-                    else if (getBit() == i_r.getBit())
-                    {
-                        return (getAttnType() < i_r.getAttnType());
-                    }
-                }
-            }
-        }
-
-        return false;
-    }
-};
-
-} // end namespace libhei