XK300 Essence

The XK Essence transmits heart rate statistics, respiratory rate statistics, and sleep data collected passively without requiring patient interaction. Data is collected in configurable intervals (as granular as 60-minute increments) and transmitted every 6 hours.

Metrics

Name	API Format	Value 1	Value 2
Heart Rate Statistics	xk_heart_rate_statistics	Median Heart Rate (BPM)	Heart Rate POBC Score
Respiratory Rate Statistics	xk_respiratory_rate_statistics	Median Respiratory Rate (Breaths/min)	Respiratory Rate POBC Score
Sleep Data	xk_sleep_data	Sleep Duration (minutes)	In-Bed Duration (minutes)

Sample patient context

The following visualizations use sample data for a fictional “Patient A” — a 68-year-old with a stable resting HR around 72 BPM and RR around 16 breaths/min. On Day 5, Patient A develops an upper respiratory infection, causing elevated heart rate and respiratory rate, triggering POBC warning scores.

Heart Rate & Respiratory Rate

Display median heart rate and median respiratory rate over time. Two approaches are recommended depending on available screen real estate.

Option A: Combined Dual-Line Chart

Combines both metrics into a single chart so clinicians can quickly identify correlation between heart rate and respiratory rate changes.

Heart rate & respiratory rate — Patient A (7-day view)

Heart rate (BPM)Respiratory rate (breaths/min)

Spec	Value
Chart type	Dual-axis line chart
X-axis	Time (day, with ability to zoom to hourly)
Left Y-axis	Heart rate (BPM), range 40–130
Right Y-axis	Respiratory rate (breaths/min), range 8–30
Time controls	Day / week / month selector with zoom capability

Option B: Stacked Separate Charts

Separate charts for each metric, stacked vertically. Scales are independent and easier to read at a glance, especially when displayed in narrow panels.

Heart rate — Patient A (7-day view)

Median heart rate (BPM)

Respiratory rate — Patient A (7-day view)

Median respiratory rate (breaths/min)

Spec	Value
Chart type	Single-axis line chart (one per metric)
X-axis	Time (day, with ability to zoom to hourly)
Y-axis (HR)	BPM, range 40–130
Y-axis (RR)	Breaths/min, range 8–30
Advantage	Clearer individual scale reading; works in narrow panels

Time scope controls

Provide the ability to adjust the timespan of data — allowing clinicians to view an entire day, week, or month while having the ability to zoom into a specific hour. This is critical for correlating changes with clinical events.

Sleep Measurement

Sleep duration and in-bed duration are combined into a single stacked bar chart. This allows clinicians to quickly review many days of data to identify trends and patterns.

Day grouping rule

Group sleep data using noon as the demarcation point between days. This ensures whole nights are counted for a single day and sleep data for one night isn’t split across two different days.

Sleep pattern — Patient A (7-day view)

Noon-to-noon grouping. Y-axis = time of day, X-axis = day.

SleepingIn bed, not sleepingNot in bed

Spec	Value
Chart type	Stacked vertical bar chart
X-axis	Day of week
Y-axis	Time of day (noon-to-noon, inverted so evening is at top)
Green bars	In bed and sleeping (#2d8a5e)
Red bars	In bed but not sleeping (#c94444 at 70% opacity)
No color	Not in bed (background shows through)
Day boundary	Noon (12:00) — ensures whole nights are grouped together

---

POBC Deviations

What is POBC?

The Probability of Change in Condition (POBC) score quantifies how unusual a patient’s recent readings are compared to their personal baseline. Learn more about the POBC score.

The POBC score is presented as a line graph with color-coded warning zones. Separate charts are shown for heart rate and respiratory rate deviations.

Heart rate POBC — Patient A (24-hour view, Day 5)

Normal range (-80 to +80)Warning zone (above +80 or below -80)

Respiratory rate POBC — Patient A (24-hour view, Day 5)

Normal range (-80 to +80)Warning zone

Spec	Value
Chart type	Line chart with color-coded segments
Y-axis	POBC score, min -100 / max +100
X-axis	Time in hours, show 24 hours at a time
Blue line	Score between -80 and +80 (normal)
Red line	Score above +80 or below -80 (warning — clinical assessment needed)
Threshold lines	Dashed red at +80 and -80
Value 123	Exclude from chart — signifies insufficient data
Separate charts	Heart rate and respiratory rate POBC are independent; display as separate charts

Handling value 123

A POBC value of 123 (or blank) indicates insufficient data to calculate a score. These values should not be plotted on the chart. Instead, show a gap in the line or display a “collecting data” indicator for that time period.