```xml
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ns4:query_definition xmlns:ns2="http://www.i2b2.org/xsd/cell/crc/psm/1.1/" xmlns:ns4="http://www.i2b2.org/xsd/cell/crc/psm/querydefinition/1.1/" xmlns:ns3="http://www.i2b2.org/xsd/cell/crc/psm/analysisdefinition/1.1/">
    <query_name>Essential hyper@10:06:02</query_name>
    <query_timing>ANY</query_timing>
    <specificity_scale>0</specificity_scale>
    <panel>
        <panel_number>1</panel_number>
        <panel_timing>ANY</panel_timing>
        <panel_accuracy_scale>100</panel_accuracy_scale>
        <invert>0</invert>
        <total_item_occurrences>1</total_item_occurrences>
        <item>
            <hlevel>4</hlevel>
            <item_name>Essential hypertension</item_name>
            <item_key>\\i2b2_DIAG\i2b2\Diagnoses\Circulatory system (390-459)\Hypertensive disease (401-405)\(401) Essential hypertension\</item_key>
            <item_icon>FA</item_icon>
            <tooltip>Diagnoses \ Circulatory system \ Hypertensive disease \ Essential hypertension</tooltip>
            <class>ENC</class>
            <item_is_synonym>false</item_is_synonym>
        </item>
    </panel>
</ns4:query_definition>

```

I want to find all patients with a diagnosis of essential hypertension in the i2b2 database, with any specificity scale, and with a high level of accuracy (1000%) and a single occurrence of the condition. The query will include only one panel and the condition should be coded as "Essential hypertension" under the "Diagnoses" category in the "Circulatory system" section, specifically under the "Hypertensive disease" subcategory. The query will not include synonyms or similar conditions, and the timeframe is not restricted.