Alteplase Dosing for Stroke to be used by an EvidenceVariable resource

{
  "resourceType" : "ActivityDefinition",
  "id" : "example-alteplase-dosing",
  "text" : {
    "status" : "generated",
    "div" : "<div xmlns=\"http://www.w3.org/1999/xhtml\">\n      \n      <p>\n        &quot;Alteplase Dosing for Stroke&quot; defines a dosing instruction referenced from an EvidenceVariable resource.\n      </p>\n\t\n    </div>"
  },
  "url" : "http://example.org/fhir/ActivityDefinition/example-alteplase-dosing",
  "identifier" : [{
    "system" : "urn:ietf:rfc:3986",
    "value" : "urn:oid:2.16.840.1.113883.4.642.19.3"
  }],
  "name" : "AlteplaseDosingForStroke",
  "title" : "Alteplase Dosing for Stroke",
  "status" : "draft",
  "description" : "Alteplase Dosing for Stroke",
  "kind" : "MedicationRequest",
  "code" : {
    "coding" : [{
      "system" : "http://www.nlm.nih.gov/research/umls/rxnorm",
      "code" : "1155608",
      "display" : "alteplase injectable product"
    }]
  },
  "intent" : "order",
  "dosage" : [{
    "sequence" : 1,
    "text" : "give 10% of dose over 1 minute",
    "route" : {
      "coding" : [{
        "system" : "http://snomed.info/sct",
        "code" : "47625008",
        "display" : "Intravenous use"
      }]
    },
    "doseAndRate" : [{
      "type" : {
        "coding" : [{
          "system" : "http://terminology.hl7.org/CodeSystem/dose-rate-type",
          "code" : "calculated",
          "display" : "Calculated"
        }]
      },
      "doseQuantity" : {
        "value" : 0.9,
        "system" : "http://unitsofmeasure.org",
        "code" : "mg/kg"
      }
    }],
    "maxDosePerAdministration" : {
      "value" : 90,
      "system" : "http://unitsofmeasure.org",
      "code" : "mg"
    }
  },
  {
    "sequence" : 2,
    "text" : "give remaining 90% of dose over 1 hour",
    "route" : {
      "coding" : [{
        "system" : "http://snomed.info/sct",
        "code" : "47625008",
        "display" : "Intravenous use"
      }]
    },
    "doseAndRate" : [{
      "type" : {
        "coding" : [{
          "system" : "http://terminology.hl7.org/CodeSystem/dose-rate-type",
          "code" : "calculated",
          "display" : "Calculated"
        }]
      },
      "doseQuantity" : {
        "value" : 0.9,
        "system" : "http://unitsofmeasure.org",
        "code" : "mg/kg"
      }
    }],
    "maxDosePerAdministration" : {
      "value" : 90,
      "system" : "http://unitsofmeasure.org",
      "code" : "mg"
    }
  }]
}