K981284 · Circulatory Technology, Inc. · DTN · Aug 12, 1998 · Cardiovascular
Device Facts
Record ID
K981284
Device Name
BETTER-BLADDER (BB)
Applicant
Circulatory Technology, Inc.
Product Code
DTN · Cardiovascular
Decision Date
Aug 12, 1998
Decision
SESE
Submission Type
Traditional
Regulation
21 CFR 870.4400
Device Class
Class 2
Indications for Use
The Better-Bladder™ is a device that isolates pressure transducers from blood contact when measurements of blood pressure in extracorporeal circuits are made during short and long term procedures. The pressure signal can be used to control pump speed. It is also used as an inline reservoir to provide compliance in the circuit during short and long term procedures.
Device Story
Better-Bladder™ (BB) is a flow-through extracorporeal circuit component; functions as pressure transducer isolator and inline blood reservoir. Device consists of unitary length of medical-grade PVC tubing with enlarged, thin-walled section housed in PETG; design eliminates physical/chemical discontinuities found in traditional bladders. Operates by sensing pressure differences across thin-walled section; provides pressure signal for pump speed control. Used in clinical settings (e.g., perfusion circuits) by clinicians. Unlike predicate bladders requiring horizontal placement, BB allows vertical orientation for gravitational washout, reducing stasis/thrombosis risk. Flow-through design prevents stagnation common in dead-ended pressure lines. Adjustable compliance reduces pressure oscillations from roller pumps. Enables shorter venous tubing, reducing prime volume and foreign surface exposure. Output is pressure signal used by external monitor to control pump speed.
Clinical Evidence
Bench testing only. Evaluated pressure measurement accuracy against invasive methods; demonstrated equivalence. Tested structural integrity with internal pressures up to 1500 mmHg (3x max clinical pressure) and housing pressure of 900 mmHg (1.8x max clinical pressure) without failure. No clinical data provided.
Technological Characteristics
Materials: Medical grade PVC (blood path, ISO 10993 compliant), PETG (housing). Design: Unitary extruded tubing with enlarged thin-walled section; flow-through configuration. Dimensions: Not specified. Energy: Passive (mechanical pressure sensing). Connectivity: Standalone component in extracorporeal circuit. Sterilization: Not specified (refers to K964337).
Indications for Use
Indicated for use in extracorporeal circuits during short or long-term procedures to isolate pressure transducers from blood contact, provide an inline blood reservoir, and facilitate pressure-based pump speed control.
Regulatory Classification
Identification
A cardiopulmonary bypass blood reservoir is a device used in conjunction with short-term extracorporeal circulation devices to hold a reserve supply of blood in the bypass circulation.
Special Controls
*Classification.* Class II (special controls), except that a reservoir that contains a defoamer or filter is classified into the same class as the defoamer or filter. The device, when it is a cardiopulmonary bypass blood reservoir that does not contain defoamers or blood filters, is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 870.9.
{0}------------------------------------------------
K981/284
#### SAFETY AND EFFECTIVENESS
### 510(k) Summary
Once a substantial equivalence determination is made, a 510(k) summary providing information on the safety and effectiveness of the Better-Bladder™ will be provided upon the request of any person. The 510(k) summary is included in Attachment 5.
### Functional Testing
With respect to this notification, the Better-Bladder™ was functionally evaluated in a series of bench tests. The test protocols, experimental data, and analyses are provided as Attachment 6. These tests and the data obtained demonstrate that the pressure measured noninvasively with the BB is equivalent to that measured invasively, and that the BB shows comparable or superior performance to the predicate devices.
General Safety See K964337.
See K964337.
Sterilization, Sterilant Residuals, Pyrogenicity See K964337.
Biocompatibility See K964337.
Quality Assurance See K964337.
{1}------------------------------------------------
## SUBSTANTIAL EQUIVALENCE
### Predicate Devices
The Better-Bladder™ is substantially equivalent to the following devices:
#### Company Name
Quest Medical (formerly Delta Medical Industries) SciMed Surgical (now AVECOR Cardiovascular)
Product Name (Model) Pressure Monitoring Separator Chamber (PMS-2) R30 Assist Reservoir
These devices are currently available cardiovascular and/or dialysis devices that have been determined to be substantially equivalent to devices in commercial distribution prior to May 28, 1976.
### Same Intended Use
## The Better-Bladder™
The Better-Bladder™ (BB) has two intended uses:
- To isolate pressure transducers from blood contact when measurements of blood pressure in extracorporeal 1. circuits are made during short or long term procedures.
- As an inline blood reservoir. such as the bladders used to sense decreasing pump inlet pressure. The pressure 2. signal can be used to control pump speed during short or long term procedures.
## Predicate Devices
The Quest Pressure Monitoring Separator Chamber is intended to help in the monitoring of arterial pressure by providing an air-liquid phase separator (same as BB use 1).
The R30 Assist Reservoir is intended to hold a reserve supply of blood in the perfusion circuit and is designed to sense venous return pressure during ECMO procedures (same as BB use 2). It incorporates two vent tubes at the top for air aspiration or drug infusion.
### Technological Characteristics
The technological characteristics of the BB do not affectiveness. The equivalency of the blood contacting portion of the BB with respect to a) material, b) design, c) general manufacturing methods, and d) use in an extracorporeal circuit is discussed below.
Material. The blood of the patient is only exposed to the inner surface of the tubing forming the BB. The a) blood path of the BB consists of a medical grade tubing extruded from a polyvinyl chloride formulation that has passed biocompatibility tests in accordance with ISO 10993 Part-1 Biological Evaluation of Medical Devices.
b) Design. The BB consists of a unitary length of tubing, a section of which has been processed to form an enlarged diameter with a thinner wall. The enlarged section is very responsive to pressure differences across its thin wall. Because the entire device is made from a single length of smooth perfusion tubing, there are no connections between the thinker wall tubing portions. This unique design eliminates both physical and material (chemical) discontinuities. The thin walled section in its housing can withstand over 1500 mmHg (three times the maximum pressure expected under worst-case clinical conditions). The BB does not incorporate vent tubes for air aspiration or drug infusion. These can be added by placing a perfusion connector with a dual Luer fitting (e.g. Avecor Model # DL1414) at the inlet to the BB, see Fig. 7b.
{2}------------------------------------------------
c) General Manufacturing. The blood path of the BB is an extruded tube, part of which is formed in a
secondary operation. The Housing of the BB, made of PETG, does not contact the patient and therefore its physical characteristics, rather then its blood compatibility, are important. Each BB is individually tested to an internal pressure as well as a Housing pressure of 900 mmHg, which is 1.8 times the maximum clinically expected pressure and also significantly higher than the maximum operating pressures recommended for many devices in the extracorporeal circuit. Tests have also been conducted where a pressure of 1500 mmHg was applied internally to the BB without any failure.
The thin walled section of the unitary tubing forming the BB is sealed within the Housing by forming a bond between the outside of the unitary tubing and the inside of the Housing. The bonding is external to the blood path and therefore does not pose any blood compatibility concerns.
d) Use in an extracorporeal circuit. Most extracorporeal circuits monitor pump inlet and/or pump outlet pressures, but typically with "dead-ended" pressure lines. Since the BB is a flow-through device, stagnation is eliminated and the likelihood of thrombosis is decreased. The predicate bladders must be positioned horizontally, and are thereby susceptible to stasis and blood cell accumulation at the bottom of the device (see Fig. 7A), which can contribute to thrombus formation.
# HOW THE BETTER-BLADDER™ ENHANCES SAFETY AND EFFECTIVENESS
- 1. The bubble in the tube is formed such that its internal surface is continuous and fissureless, thereby eliminating chemical or physical discontinuities, factors that can increase thrombus formation.
- In terms of bladders, the predicate bladders must be positioned horizontally, and are thereby susceptible to 2. stasis and blood cell accumulation at the bottom of the device, both of which can contribute to thrombus formation. The BB can be placed vertically, thus providing gravitational washout that significantly reduces stasis or accumulation of red cells (see Fig. 7).
- 3. The BB can provide adjustable compliance that reduces pressure oscillations due to pumping action of the roller pump.
- 4. The predicate bladder must be placed on the floor to achieve appropriate gravitational flow. The BB, however, can be placed much closer to the patient with the loss of "gravity" drainage compensated by applying slight negative pressure to the housing. This allows for shorter venous tubing which reduces the prime volume, the foreign surface exposed to blood as well as the of the blood to the surface. The shorter circuit and smaller surface area also reduces heat loss of the blood in the extracorporeal circuit.
- 5. In terms of pressure isolators, the BB is a flow-through device, reducing the chance of clotting. The predicate devices can pose greater risk of clotting because there is NO flow in the pressure line connecting the blood path to the isolator.
- 6. If the BB is used to obtain a pressure signal to control the pressure at which the purnp would turn off is easily adjustable via the pressure monitor. The predicate bladder relies on a mechanical switch and is not adjustable.
Image /page/2/Figure/13 description: The image shows two diagrams, labeled A and B, illustrating flow conditions with predicate devices. Diagram A shows a silicone bladder with blood inside, and the text indicates that blood cells settle in this configuration. Diagram B depicts a perfusion connector with two stopcocks, and the text indicates that blood cells wash through in this setup. The diagrams are part of Figure 7 and reference 'The Better-Bladder™'.
{3}------------------------------------------------
Image /page/3/Picture/1 description: The image shows the logo for the U.S. Department of Health & Human Services. The logo consists of a circular seal with the text "DEPARTMENT OF HEALTH & HUMAN SERVICES · USA" around the perimeter. Inside the circle is an abstract image of an eagle or other bird-like figure with three stylized lines representing its wings or feathers.
Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850
AUG 1 2 1998
Mr. Yehuda Tamari President Circulatory Technology, Inc. 21 Singworth Street Oyster Bay, NY 11771
K981284 Re: "Better-Bladder™" Requlatory Class: II Product Code: DTN Dated: May 13, 1998 Received: May 14, 1998
Dear Mr. Tamari:
We have reviewed your Section 510(k) notification of intent to market the device referenced above and we have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Druq, and Cosmetic Act (Act). You may, therefore, market the device, subject to the general controls provisions of the Act. The general controls provisions of the Act include requirements for annual registration, listing of devices, qood manufacturing practice, labeling, and prohibitions against misbranding and adulteration.
If your device is classified (see above) into either class II (Special Controls) or class III (Premarket Approval), it may be subject to such additional controls. Existing major requlations affecting your device can be found in the Code of Federal Requlations, Title 21, Parts 800 to 895. A substantially equivalent determination assumes compliance with the Current Good Manufacturing Practice requirements, as set forth in the Quality System Regulation (QS) for Medical Devices: General regulation (21 CFR Part 820) and that, through periodic QS inspections, the Food and Drug Administration (FDA) will verify such assumptions. Failure to comply with the GMP regulation may result in requlatory action. In addition, FDA may publish further announcements concerning your device in the Federal Register. Please note: this response to your premarket notification submission does not affect any obliqation you might have under sections 531 through 542 of the Act for devices under the Electronic Product Radiation Control provisions, or other Federal laws or requlations.
{4}------------------------------------------------
#### Paqe 2 - Mr. Yehuda Tamari
This letter will allow you to begin marketing your device as described in your 510(k) premarket notification. The FDA finding of substantial equivalence of your device to a legally marketed predicate device results in a classification for your device and Ehus, permits your device to proceed to the market.
If you desire specific advice for your device on our labeling regulation (21 CFR Part 801 and additionally 809.10 for in vitro diagnostic devices), please contact the Office of Compliance at (301) 594-4648. Additionally, for questions on the promotion and advertising of your device, please contact the Office of Compliance at (301) 594-4639. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21CFR 807.97). Other general information on your responsibilities under the Act may be obtained from the Division of Small Manufacturers Assistance at its toll-free number (800) 638-2041 or (301) 443-6597 or at its internet address "http://www.fda.gov/cdrh/dsma/dsmamain.html."
Sincerely yours,
Thomas J. Callahan
Thomas J. Callahan, Ph.D. Director Division of Cardiovascular, Respiratory, and Neurological Devices Office of Device Evaluation Center for Devices and Radiological Health
Enclosure
{5}------------------------------------------------
Image /page/5/Picture/1 description: The image shows a close-up of what appears to be a cane or walking stick. The top portion is a long, cylindrical shape, while the bottom portion is a rounded handle. The image is in black and white, and the details are somewhat obscured by the contrast.
Attachment 10 Better-Bladder™ Indications for Use
510(k) Number Device Name:
K98 1284-
Better-Bladder тм
The Better-Bladder™ is a device that isolates pressure transducers from blood contact Indications for Use: when measurements of blood pressure in extracorporeal circuits are made during short and long term procedures. The pressure signal can be used to control pump speed. It is also used as an inline reservoir to provide compliance in the circuit during short and long term procedures.
981284
(Division Sign-Off) Division of Cardiovascular, Respiratory, and Neurological Devices 510(k) Number_
age 1
Image /page/5/Picture/10 description: The image shows a close-up, black-and-white photograph of what appears to be a portion of a rock or mineral. The texture is rough and uneven, with a mix of light and dark areas creating a mottled effect. The lighting suggests a strong contrast, highlighting the granular surface of the material. The composition focuses on the texture and form of the rock, with no other discernible objects or background elements present.
Predicate graph will load when search results are available.
Embedding visualization will load when search results are available.
PDF viewer will load when search results are available.
Loading panels...
Select an item from Submissions
Click any panel, subpart, regulation, product code, or device to see details here.
Section Matches
Results will appear here.
Product Code Matches
Results will appear here.
Special Control Matches
Results will appear here.
Loading collections...
Loading
My Alerts
You will receive email notifications based on the filters and frequency you set for each alert.
Sort by:
Create Alert
Search Filters
Agent Token
Create a read-only bearer token for Claude, ChatGPT, or other agents that can call HTTP APIs.
Copy this now. It will not be shown again.
Connected apps
Apps you authorized through browser sign-in. Disconnecting revokes their access immediately.
Learn the FDA Browser
Two short videos show you everything — or skip straight to the written tutorial if you'd rather read. You can reopen this any time from the Tutorial button in the top bar.
Part 1 — Search, results, and everyday workflows 16 min
Part 2 — Embeddings: the galaxy map 3 min
1. Search: exact and fuzzy
Type a phrase like "coronary artery calcification" into the search box. You get two kinds of results. Exact results match the literal phrase — prefix searches work ("coronary artery calcificati") but suffix searches do not. Fuzzy results match on the meaning and intent of your phrase rather than the exact words, and are sorted by relevance score. Hover over the Exact or Fuzzy badge on any row to see exactly why it matched.
Use the checkboxes above the results to narrow: SaMD keeps only software-only devices, AI / ML keeps only devices with AI.
Exact vs. fuzzy search: what's the difference?
Exact matches on the literal phrase (prefix search works, suffix does not). Fuzzy matches on the meaning and intent of the phrase rather than the exact words. Hover over the badge on any row to see why it matched.
You search "coronary artery calcification" and want only software devices with AI. What two filters do you apply?
Narrow by SaMD (software-only devices), then narrow by AI/ML (devices with AI).
2. The results table
Scroll right in the results table. The intended use is extracted for you — no need to open the PDF. The device story gives a high-level snapshot of what the device does and how it's used. The AI Performance sub-table shows each output name, acceptance criteria, observed values, and development/test dataset descriptions — the same format Innolitics uses for regulatory strategy outputs, and the fastest high-level fingerprint of an AI device. It is AI-generated but has been very reliable in practice.
Where do you find a device's intended use without opening the PDF?
Scroll right in the search results table. The intended use column is extracted for you; no need to dig into the 510(k) summary PDF.
What does the AI Performance sub-table show, and why is it useful?
Output name, acceptance criteria, observed values, development dataset description, and test dataset description. It's the same format we use for regulatory strategy output and Fast 510(k) input, and the fastest high-level fingerprint of an AI device. AI-generated but reliable in practice.
3. Judging fuzzy relevance
Fuzzy results trail off in relevance as you scroll. Use three signals to decide how far down to go: the fuzzy badge explanations, the intended use column, and whether your target output (e.g., Cobb angle) still appears in the AI Performance sub-table. Once it stops appearing, you're past the relevant zone. A top hit with a low score (~0.4) and a stretched explanation is a hint the closest predicates are far away — the project may be headed for De Novo. Note the fuzzy search is a pattern match: it doesn't handle negation ("not") well, and hardware devices can appear — filter by SaMD/AI ML to cut them.
How do you judge how far down fuzzy search results to go?
Use the relevancy signals: the fuzzy badge explanations, the intended use column, and whether the target output (e.g., Cobb angle) still appears in the AI Performance sub-table. Once it stops appearing, results are trailing off in relevancy.
4. Device detail page: chat and citations
Click a device name to open its detail page: device facts on the left, a chat window on the right. Ask something like "Describe the training data". The answer carries little citation bubbles — click one to jump to the highlighted passage in the source PDF, so you can verify every AI answer against the document. There's also a Download PDF button for sharing.
How do you verify an AI chat answer on the device detail page?
Click the citation bubbles to jump to the relevant highlight in the source document.
Reading rule for every project: how many summaries do you read in full?
At least the three most relevant 510(k) or De Novo summaries, in full. After that, use targeted chat questions to confirm your memory quickly. The tool supports this professional habit — it doesn't replace it.
5. Side-by-side comparison
Select multiple rows in the results table (aim for under ~10), then open the PDF Viewer tab. Ask one question — it goes to all selected devices in parallel, each with citations. This is the fastest way to compare and contrast devices: training data, PCCP scope, how they handled adding new scanners, and so on.
What does the side-by-side PDF viewer mode do?
Select multiple devices, open the PDF viewer tab, and ask one question (e.g., "Describe the training data"). It queries all selected devices simultaneously with citations, so you can compare and contrast quickly.
6. Collections
With rows selected, go to the Collections tab and create a labeled collection (e.g., "Cobb Angle Project"). Reload that selection any time — before a client call, pull up the collection and ask questions across all of its devices at once.
How do you save a set of selected devices for later use?
Select the rows, go to the Collections tab, and create a labeled collection (e.g., "Cobb Angle Project"). You can reload the selection anytime and carry it into the PDF viewer and other tabs that support selections.
7. Product codes and the regulations tree
Click a product code in the results to jump to it in the regulations tree — identification text, sibling product codes, and devices you can open in a PDF viewer on the right. Click a regulation number to see its identification, special controls, and related product codes. You can also search by product code or regulation number at the top of the tree. Always read the special controls if any exist for your device — it broadens your search and sharpens pre-kickoff research.
What can you do from the regulations tree view?
Browse product codes and regulation numbers, read the identification text and special controls, browse sibling product codes, open device PDFs on the right, and search by product code or regulation number at the top of the tree.
8. Chart view
Click Show Chart and segment by regulation number (or product code) to see which regulations dominate your result set. Clicking a regulation takes you into the regulations tree. Great for spotting that most matches are, say, hardware laparoscopic devices — a cue to go back and filter.
How do you see which regulations dominate a search result set?
Click "Show Chart" and segment by Regulation Number. Clicking a regulation takes you to the regulations tree.
9. The predicate graph
Open the Predicates tab for a family-tree view of predicate relationships. Click a node to trace its parents and children; selections from search carry over pre-selected. Commonly predicated devices are worth reading — a lot of people predicated them for a reason. The visual lineage is also handy on client calls, e.g. to show how a predicate family evolved and justify why your predicate still holds.
In the predicate graph, why are commonly predicated devices worth reading?
A lot of people predicated them for a reason. Clicking a node traces parents and children, and selections from search carry over pre-selected.
10. Embeddings: the galaxy map
The Embeddings tab plots every matching document in a 2-D "galaxy map" where semantically similar devices cluster together. Hover or click clusters to explore, and let AI label the clusters for you. Embeddings beat product codes for grouping: two devices can carry different product codes (LLZ vs. QIH) yet do the same thing — the embedding captures the meaning of the intended use and device story. This is also exactly how retrieval-augmented generation (RAG) works under the hood, and it makes a great visual on client calls.
Try it yourself
Head to the search page and work through a few of these AI/ML fuzzy searches to build intuition: perivascular fat on CT · aortic valve calcification opportunistic screening on noncontrast CT · breast cancer prediction on digital pathology slides · autism detection · gestational age prediction · a hearing aid that can also detect a pulse · foundation model based analysis of ECG · large language models · penetration test. Watch how the relevance scores, intended use, and AI Performance tables tell you when results stop being meaningful.