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IEMI Labs
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SensingRev A design complete (stages 1-6), all hardware fit-checked in CAD, not built; human clinical use needs FDA 510(k) (code FLN) or CDSCO Class C first

DripCrown

The IV stand the ward already owns, made smart: it weighs every bag and watches every drip

A Crown replaces the hook top of an existing IV stand and weighs each bag on its own load cell (mL left, minutes left, flow from the weight slope); a DripClip camera on the drip chamber counts drops and sees a stopped drip or a free-flow stream. Alerts go to the nurse's phone and a light ring on the stand. It monitors and alerts only and never touches the flow.

Who buys it
First: veterinary clinic owners and practice managers (gravity drips are routine and animal devices need no FDA premarket review). Later, after clearance: nursing superintendents in hospitals where gravity sets are the norm (India, South and South-East Asia) and home-infusion providers. Today they rely on nurse rounds, or buy a DripAssist at about $335-480 per line or a ₹14,331 drip monitor.
Why it pays
A Finnish study valued the nurse time freed by remote gravity-infusion monitoring at about €1,271 per ward per month; a Chinese IoT study raised on-time completion from 35.6% to 47.2% over 91,300 infusions. A Bed Kit at the $249 target costs less than one DripAssist (est.).
Target price
$249 Bed Kit (Crown + 1 DripClip), $49 per extra DripClip, $6/stand/month for the ward dashboard (target)
First-minute wow
The nurse hangs a 500 mL bag and clips the camera on; within a minute the phone shows '487 mL left, 102 mL/h, empty at 14:52', and the stand ring goes amber 15 minutes before the bag runs out.
See the CAD designConcept page
DripCrown concept: the idea and where each part goes
The concept. The CAD design is below, under Printable CAD.

What the research found

And how this design answers it

  • Gravity drips are badly inaccurate (a 1985 study found under 15% of observations within ±10% of the ordered rate) → every bag is weighed, so flow and time left come from mass, not from a guessed drop factor
  • Existing drip monitors (DripAssist, Drip Alert) count drops only, and nominal drop volume shifts with fluid and rate → the weight calibrates each line's real drop volume over 30 minutes
  • Weight alone is blind at slow rates: CAD rate report shows load-cell creep is a 25-50% bias at 10-20 mL/h (est.) → below about 50 mL/h the drop camera times the line and the weight only calibrates it
  • 74% of 114,793 alerts in a Chinese ward study were blockage or rate drift, only 22% completion → DripCrown alerts on stopped flow, drift and free flow, not just 'bag empty'
  • Nurses walk room to room to check bags → a light ring visible from the corridor plus phone alerts, with the bedside buzzer off at night
  • Clip-on gadgets get lost and are another thing to buy per line → the weighing lives in the stand top the ward already owns; the clip is a cheap add-on per line

Use case

Night shift, 22 drips on a 30-bed ward

Ward nurseCharge nursePatient

  1. 01Trigger: a 500 mL saline bag on bed 14 is 15 minutes from empty and bed 9's drip has slowed to half rate because the patient bent their arm
  2. 02Detection: the Crown sees bed 14's mass approaching the end-of-bag threshold; bed 9's DripClip sees drop intervals double and the weight slope agree
  3. 03Alert: the nurse's phone shows 'Bed 14: empty in 15 min' and 'Bed 9: rate -48% for 6 min'; both stand rings turn amber
  4. 04Action: the nurse readies the next bag for bed 14 and straightens bed 9's arm; the rate recovers and the alert clears itself

Outcome: No dry line and no re-cannulation; about 20 minutes of checking rounds saved per night (est.)

How it works

Architecture

  1. 01

    Sense: two TAL220B load cells with HX711 amps in the Crown (bag mass at 10 SPS); an OV2640 camera with a pulsed amber backlight in each DripClip

  2. 02

    Decide: the DripClip's ESP32-S3 finds each drop as the hanging drop at the orifice resets, and flags a stopped drip or a continuous stream; the Crown fuses drop intervals with the weight slope

  3. 03

    Send: DripClip to Crown over encrypted ESP-NOW; Crown to the ward gateway (IEMI Edge Hub or hospital Wi-Fi) over MQTT/TLS, events only, never images

  4. 04

    Tell: nurse phones and a ward dashboard (bed, mL left, rate, time to empty), the stand's light ring, and an optional bedside chirp

Hardware

Real parts, buyable today

Bill of materials: about $101 per Bed Kit (Crown + 1 DripClip) at qty 1, about $68 at qty 100 (est.).

BlockPartWhy this part
Bag weighing2 x TAL220B 5 kg straight-bar load cell + 2 x HX711Mass gives mL left with no drop-factor guess; one cell per hook
Drop cameraSeeed XIAO ESP32-S3 Sense (OV2640), lens refocused to ~35 mmSees a 4.6 mm drop at about 80 px across (CAD framing report, est.)
Crown MCUSeeed XIAO ESP32-C3Wi-Fi to the ward, ESP-NOW to clips, built-in charger
Power18650 3,000 mAh in the Crown, LiPo 1,000 mAh in each clipCrown 8.7 days, clip 32 h per charge (est.); no cable on a moving stand
AlertAdafruit NeoPixel Ring 12 under a translucent lid + 12 mm buzzerStatus visible from the corridor

Mechanical

Printable CAD

4 parts, generated from code and checked as closed solids. Pick a part to inspect it, or download the STL files to print.

See the CAD parts render
DripCrown printable parts, rendered from the CAD
Render of the printable parts from the actual CAD. Not yet printed or photographed.

Loading the CAD…

Real CAD · drag to rotate · scroll to zoomReal CAD · swipe sideways

Open risks we are working on

  • Regulatory: in the US it is a Class II gravity-infusion monitor (21 CFR 880.2420, code FLN) needing a 510(k); India lists this device type as Class C (est., to verify); so rev A is sold to veterinary clinics and as evaluation units only
  • Patient movement and tugging the tubing change the hook load by tens of grams; step rejection plus the drop cross-check is untested (test T2)
  • In high-income hospitals most infusions already run on pumps, so the human market is mainly gravity-heavy countries, which are price-sensitive
  • Load-cell creep is estimated (no TAL220B creep spec found) and decides where weight-only timing works; test T1 on a 24 h bench run
  • A clip of about 95 g (est.) on a drip chamber may tilt it; the band and chamber fit across brands need a fit test (T3)
  • Monidor (Finland), Dripo (India) and Chinese ward systems already sell drop counters; our case is weight plus drops on a stand the ward already owns

Design stage only: nothing on this page is for sale. Specifications and prices are targets.