The Westmed, Inc. BlockAide™ Filter is designed as a disposable and single-use, bi-directional filter for use in reducing possible bacterial and/or viral cross contamination of spirometers and pulmonary function testing instruments, associated valves and hoses, from aerosols and particulates, which may be present in a patient's exhaled gas. The device is indicated for diagnostic applications.
Device Story
BlockAide™ Filter is a disposable, single-use, bi-directional barrier filter; protects patients and pulmonary function instruments from pathogen transmission via droplets and aerosols. Device consists of two molded plastic housings enclosing a disk of filter media; opaque patient-side housing and numbered machine-side housing ensure correct orientation. Available in six sizes to accommodate various spirometer sensor diameters. Used in clinical settings during diagnostic pulmonary function testing; operated by clinicians. Filter reduces bacterial and viral contaminants in exhaled gas while maintaining low airflow resistance. Benefits include reduced risk of cross-contamination between patients and protection of sensitive diagnostic equipment.
Clinical Evidence
Bench testing only. Bacterial Filtration Efficiency (BFE) and Viral Filtration Efficiency (VFE) both >99.9%. Airflow resistance measured at 0.419 cm H2O/L/sec, meeting American Thoracic Society (1994) standards (<1.5 cm H2O/L/s). Filter dead space is 54 mL. Biocompatibility testing (cytotoxicity, sensitization, intracutaneous reactivity) conducted per ISO 10993-1 confirmed the device is biocompatible for limited (<24 hours) surface and external communicating contact.
Technological Characteristics
Disposable, bi-directional barrier filter. Molded plastic housing with internal filter media disk. Six sizes available. Airflow resistance <1.5 cm H2O/L/s. Biocompatible per ISO 10993-1. Non-sterile. Mechanical filtration principle.
Indications for Use
Indicated for patients undergoing diagnostic spirometry or pulmonary function testing to reduce cross-contamination of equipment from exhaled aerosols and particulates.
Regulatory Classification
Identification
A breathing circuit bacterial filter is a device that is intended to remove microbiological and particulate matter from the gases in the breathing circuit.
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#### 4.0 510(k) Summary
In accordance with 21 CFR sections 807.92, Westmed, Inc. is submitting the following 510(k) summary:
K1773
DEC
ﮯ ۔
#### Date of Preparation 4.1
May 18, 2012
#### Submitter Information: 4.2
Westmed, Inc. Company Representative: R. Jon McKinnon, President 5580 S. Nogales Highway Tucson, AZ 85706 United States USA FDA Registration No .: 2028807 Owner / Operator No .: 9006543
#### Preparer of Submission and Contact for Information: 4.2
Westmed, Inc 5580 S. Nogales Highway Tucson, AZ 85706 United States Telephone: (800) 724-2328 / Fax: (520) 294-2780
R. Jon McKinnon (contact for correspondence and information) Telephone: (800) 724-2328 / Fax (520) 294-2780
#### 4.3 Name of Device:
| Proprietary Name: | BlockAide™ Filter. |
|----------------------|----------------------------------------------------------------|
| Common Name: | Disposable bacterial/viral filter. |
| Classification Name: | Breathing circuit bacterial filter, [21 CFR 868.5260(a)]. |
| Regulation Number: | 21 CFR 868.5260(a) for Breathing circuit bacterial<br>filters. |
| Product Code: | 73 CAH |
| Class: | Class II (performance standards) |
Page 9 of 115
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#### Substantial Equivalence: 4.4
This submission establishes the substantial equivalence of the Westmed, Inc. BlockAide™ Filter to five predicate devices:
- The All Flow Pulmonary Filter, (1)
K043148, SE letter: 12/13/04.
- The SpiroSafe Disposable PF Filter, (2) (3)
K973314, SE letter: 11/21/97. K934475, SE letter: 10/21/93.
- The KOKO Disposable PF Filter II, The MicroGard Disposable PF Filter,
- K934272, SE letter: 11/24/93.
- The MultiSPIRO Disposable PF Filter, K951410, SE letter: 04/24/95. (5)
#### Description of the Device: 4.5
(4)
The BlockAide™ Filter, manufactured by Westmed, Inc., is a disposable, single-use barrier type, bi-directional filter fabricated from a plastic resin that is supplied to the customer packaged and non-sterile. Fabricated with a filtering medium that is highly effective in reducing the numbers of both bacterial and viral contaminates that may be present in a patient's exhaled gas, the device's design also minimizes the resistance to air flow. The product is intended to protect both the patient and pulmonary function instruments from potential transmission of pathogens by droplets and aerosols.
The device consists of two molded plastic housings enclosing a disk of filter media. To avoid confusion, the patient housing side is made from an opaque plastic and the machine housings are fabricated from the same plastic but with different number molded into the housing to identify machine end. The numbered end fits the machine and the opaque end is for the patient side; therefore making clear definition as to which end is used for the patient and the machine.
Figure I Example of Filter Part No. 6901-E with patient and machine housing components separated:
Image /page/1/Picture/14 description: The image shows three circular objects on a dark background. Two of the objects appear to be the lids of containers, with intricate designs and a hole in the center. The third object is a solid, round disc with a textured surface, and an arrow points towards it.
Opaque machine housing with number
Filter medium Page 10 of 115 Opaque patient housing with mp
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### Figure 2, Example of filter assembled:
Image /page/2/Picture/2 description: The image shows a dark, grainy photo of a vase. The vase is dark in color and has a rounded body with a cylindrical neck. The background is black, which makes it difficult to see the details of the vase. The image is low quality and has a lot of noise.
Because spirometers can have different sensor diameters, the BlockAide™ Filter is available in six different sizes with a number that correlates with their respective part numbers. The following chart lists the size and number of each model:
### Filter Chart
| BlockAide™ Filter<br>Part No. | number combination<br>(patient housing / machine<br>housing) | I.D / O.D (mm) |
|-------------------------------|--------------------------------------------------------------|----------------|
| 6901-R/E | Opaque / Opaque 1 | 27.23 / 30.18 |
| 6902-R/E | Opaque / Opaque 2 | 34.48 / 33.15 |
| 6903-R/E | Opaque / Opaque 3 | 45.47 / 47.45 |
| 6904-R/E | Opaque / Opaque 4 | 26.26 / 28.73 |
| 6905-R/E | Opaque / Opaque 5 | 29.52 / 32.77 |
| 6906-R/E | Opaque / Opaque 6 | 37.39 / 33.63 |
#### Intended Use of the Device: 4.6
The BlockAide™ Filter is designed as a disposable and single-use bi-directional filter for use in reducing possible bacterial and/or viral cross contamination of spirometers and pulmonary function testing instruments, associated valves and hoses, from aerosols and particulates, which may be present in a patient's exhaled gas. The device is indicated for diagnostic purposes.
#### Technological Characteristics in Comparison to the Predicates: 4.7
The BlockAide™ Filter has no differences in Technological characteristics and is substantially equivalent to the five predicate devices with respect to the following design characteristics and functions:
- The devices are intended for use in reducing the possible cross contamination 1. of spirometers and pulmonary function testing instruments from bacterial and/or viral pathogens by droplets, particulates, and/or aerosols.
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- The devices function as a barrier type, bi-directional filter, which is within a 2. sealed double port assembly, with one port contacting the patient's mouth and the other port to be attached to the spirometers or pulmonary function-testing instrument.
- The device housing components are fabricated from the same or similar 3. The 'donoo noderials used in the predicate devices. The filter media is the same as or similar to that used in the predicate devices. These materials have long and extensive use in medical device applications.
- The devices have been demonstrated to function effectively in reducing high 4. challenge numbers of bacterial and viral contaminates.
- The devices provide air filtration while minimizing alrflow resistance through ട്. the filter assemblies to the pulmonary test equipment.
- The BlockAide™ Filter met the recommendations of the American Thoracic 6. Society's Standardization of Spirometry (1994 update) for minimal Society S - Otandardization - of Spirometry Equipment with in-line filters; i.e., that the measuring equipment as attached to the filter have air flow resistance of less than 1.5 cm H₂O/L/s.
#### Conclusions drawn from the Non-Clinical Tests: 4.8
1.
Data provided in this submission indicate that the basic functional characteristics of the BlockAide™ Filter are substantially equivalent to those of the predicate devices.
- Bacterial Filtration Efficiency (BFE) testing demonstrated the BlockAide™ Filter, at an increased chailenge, to be %BFE = > 99.9%.
Viral Filtration Efficiency (VFE) testing demonstrated the BlockAide™ filter, at an increased challenge, to be %VFE = > 99.9%.
- Airflow resistance testing demonstrated the device to an average of 5.028 cm ' 2. H2O/SLPM at 720 L. (Ref. 760 mm HGA 70 °F), which is approximately 0.419 cm H2O/L/sec.
- Filter dead space was demonstrated to be approximately 54 mL. 3.
- The BlockAide™ Filter meets the recommendations of the American Thoracic 4. Society's Standardization of Spirtometry (1994 update) for minimal recommendations for Diagnostic Spirometry Equipment with in-line filters i.e., that the measuring equipment as attached to the filter have air flow resistance of less than 1.5cm H2O/L/s.
- The device was categorized as a surface device with skin and mucosal 5. membrane and as an external communicating device with tissue contact both for limited <24 hours contact. As such per FDA Memorandum G-95 Table 1 the following tests were conducted per ISO 10993-1 cytotoxicity, sensitization and intracutaneous reactivity. This testing showed the device to be biocompatible.
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## DEPARTMENT OF HEALTH & HUMAN SERVICES
Image /page/4/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 words "DEPARTMENT OF HEALTH & HUMAN SERVICES • USA" around the perimeter. Inside the circle is a stylized symbol that resembles three overlapping human figures.
Food and Drug Administration 10903 New Hampshire Avenue Document Control Center - WO66-G609 Silver Spring, MD 20993-002
Public Health Service
## December 6, 2012
Mr. R. Jon McKinnon President Westmed, Incorporated 5580 South Nogales Highway TUCSON AZ 85706
Re: K121382
Trade/Device Name: BlockAide™ Filter Regulation Number: 21 CFR 868.5260 Regulation Name: Breathing Circuit Bacterial Filter Regulatory Class: II Product Code: CAH Dated: November 14, 2012 Received: November 23, 2012
Dear Mr. McKinnon:
We have reviewed your Section 510(k) premarket notification of intent to market the device referenced above and 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, Drug, and Cosmetic Act (Act) that do not require approval of a premarket approval application (PMA). 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, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you, however, that device labeling must be truthful and not misleading.
If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.
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Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Part 801); medical device reporting (reporting of medical device-related adverse events) (21 CFR 803); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820); and if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.
If you desire specific advice for your device on our labeling regulation (21 CFR Part 801), please go to http://www.fda.gov/AboutFDA/CentersOffices/CDRH/CDRHOffices/ucm115809.htm for the Center for Devices and Radiological Health's (CDRH's) Office of Compliance. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21CFR Part 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to
http://www.fda.gov/MedicalDevices/Safety/ReportaProblem/default.htm for the CDRH's Office of Surveillance and Biometrics/Division of Postmarket Surveillance.
You may obtain other general information on your responsibilities under the Act from the Division of Small Manufacturers, International and Consumer Assistance at its toll-free number (800) 638-2041 or (301) 796-7100 or at its Internet address
http://www.fda.gov/MedicalDevices/Resourcesfor You/Industry/default.htm.
Sincerely yours,
# Kwame Q. Ulmer
Anthony D. Watson, B.S., M.S., M.B.A. Director
Division of Anesthesiology, General Hospital, Respiratory, Infection Control and Dental Devices
Office of Device Evaluation Center for Devices and
Radiological Health
Enclosure
{6}------------------------------------------------
## INDICATIONS FOR USE STATEMENT
## 510(k) Number (if known): K121382
BlockAide™ Filter Device Name:
## Indications for Use:
The Westmed, Inc. BlockAide™ Filter is designed as a disposable and single-use, bi-directional The Wolthou, in reducing possible bacterial and/or viral cross contamination of spirometers and hiter for ass in roducing poculars, associated valves and hoses, from aerosols and particulates, which may be present in a patient's exhaled gas. The device is indicated for diagnostic applications.
2 OR Prescription Use (part 21 CFR 801. Subpart D)
Over-the-Counter Use (part 21 CFR 801 Subpart C)
(PLEASE NO NOT WRITE BELOW THIS LINE -- CONTINUE ON ANOTHER PAGE IF NEEDED)
Concurrence of CRDH, Office of Device Evaluation (ODE)
Lester W. Schultheis Jr 2012.12.07 1/2:36:36 -05'00'
(Division Sign-Off) (Division Sign-Off)
Division of Anesthesiology, General Hospital
Division of Anesthesiology, General Devices Division of Arcol. Dental Devices
K121382 . 510(k) Number:
000010 Rev A
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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.
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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?
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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.
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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.
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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.
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Reading rule for every project: how many summaries do you read in full?
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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.
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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.
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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.