IDE Protocol Fingerstick Consistency Issue¶
Updated: 2026-09-04
| Field | Value |
|---|---|
| Status | Closed in the final protocol and consent document set |
| Source | Clinical Protocol BLS Clean-final.docx; Optimizing Automated Insulin Delivery to Meet Pregnancy Glycemic Targets, Version 1.0, version date 1 September 2026, 41 pages; SHA-256 4bfb09542230c94c00dc5b5331a969657b5961b1c4bbd5a2759519a00f71d264 |
| Affected software areas | Manual BG, CGM outage, algorithm mode, alerts, transition behavior |
| Clinical approval | Camille Powe, MD approved the distinct safeguarded fingerstick direction on 2026-08-27 and approved implementation of the related protocol/consent recommendations on 2026-08-31 |
Historical Protocol Discrepancy¶
The June protocol stated that entered fingerstick BG measurements would be treated as Dexcom CGM data. That statement did not describe the implemented software accurately.
Implemented Behavior¶
The frozen software does not treat a fingerstick value as an ordinary Dexcom CGM sample. It uses a distinct BG-based closed-loop path with controls that include:
- manual range and completeness validation
- explicit exact-value user confirmation
- step-scoped pending validity and exactly-once consumption
- BG-specific timing and due/overdue scheduling during sustained CGM outage
- BG-specific alerting and Home presentation
- shared input to both algorithm copies only on the qualifying step
- explicit transitions between CGM-based, BG-based, and forced-open behavior
- no step-0 BG rescue in the frozen baseline
The historical wording therefore overstated equivalence between a fingerstick BG and Dexcom CGM data.
Verified Final Protocol Direction¶
If Dexcom CGM data are unavailable, a participant may enter and confirm a fingerstick BG. BionicLoop processes the value through a distinct BG-based closed-loop mode with BG-specific timing, validity, alert, and transition safeguards. The value is available to the next eligible algorithm step, is consumed once, and may result in automated insulin delivery. The Dexcom G7 should be restored or replaced as soon as possible.
The final protocol describes the distinct safeguarded fingerstick mode, next eligible step, and exactly-once consumption consistently with this direction. The clinical protocol remains controlled outside this software repository.
Required Disposition¶
| Decision | Owner/status |
|---|---|
| Confirm the intended clinical role of fingerstick BG during CGM outage | Approved by Camille Powe, MD on 2026-08-27 |
| Approve direction to replace the Dexcom-equivalence statement with wording consistent with implemented behavior | Approved by Camille Powe, MD on 2026-08-27 |
| Confirm the final consent and IFU provide participant-facing CGM-outage instructions | Closed by the final consent document and current IFU revision 1.17 |
The software consistency issue is resolved in the final protocol, consent, and IFU document set. The approved clinical direction is retained in the Clinical Approval of Software IDE Decisions. The broader June-document review and proposed wording are recorded in the Software Consistency Crosswalk.