Medical Devices: The Oximeter

An Oximeter is a device used to transmit radiation through blood and to measure the blood oxygen saturation. ()These are non-invasive and efficient devices used to determine oxygen levels during surgery, anesthesia, respiratory failures, in premature infants and also in examination of sleep disorders. () It is extensively used in the early determination of hypoxemia, which may be dangerous resulting in brain damage. ()

The major contribution of Oximeter to the field of medical devices is safety, as there is no electrical contact between the person and the medical device. In patients associated with risks of respiratory failures it is important to understand and determine oxygen saturation in blood. So in such cases it is important to continuously monitor patient’s condition. All of these can be successfully achieved through the use of Oximeters. ()

Examples of Oximeter that are commonly used are Quanta Pulse Oximeter, Accupulse Oximeter, finger pulse oximeter etc.

Finger Pulse Oximeter

Predicate devices: MD300C I Fingertip pulse oximeter()

Device design: These devices are designed to operate continuously for 24 hrs through alkaline batteries. Power consumption is less with these devices and upon low battery, a warning signal is observed. ()

Features: Some of the main features of finger pulse oximeter include Accuracy and reliability: The most important specification in selecting a finger pulse oximeter is its accuracy and reliability. These Oximeters produce accurate results within fraction of seconds and has an accuracy of +3%.

Ease of use: These Oximeters can be easily even by elderly people by just placing finger into the sensor and then the button is pressed.

Memory: Results can be stored for future analysis. Results of multiple people can also be saved.

Size: Because of its smaller size it can be easily handled, stored. ()

Classification: It is a class II device, so these devices require pre-market notification [510(k) clearance] and are subjected to both general controls and special controls. Different types of premarket notifications include Traditional, special and abbreviated. 510(k) submission process is mainly based on the principle of substantial equivalence to a marketed device.

Since these are class II devices they are subjected to both general controls and special controls. General controls include establishment registration (21 CFR 807), Device Listing (21 CFR part 862 to 892), Medical Device Reporting (21 CFR 803), Quality System Regulation, labeling requirements as per 21 CFR 801 or 21 CFR 809. If general controls alone are not sufficient to determine the safety and efficacy of devices then they are subjected to special controls. Special controls include post market surveillance, special labeling requirements, performance standards etc. () Preclinical and clinical tests are conducted to determine the safety of device. Then manufacturers are required to submit a premarket notification (510k) to FDA indicating that the device is safe and effective for use and are also substantially equivalent to a legally marketed device. The device can be marketed in US after the manufacturer receives an order from FDA. According to 21 CFR 820 there may be FDA quality system inspection after 510(k) clearance. 10(). After the device is marketed post-market surveillance is also conducted to determine its safety and efficacy in patients after marketing.

In order to provide substantial equivalence of the device it is compared with a predicator device

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The safety, performance and specifications of the new device are same as that of the legally marketed device. Certain minor differences are observed in their intended use and Pulse rate measurement range. But variations in these do not affect the safety and performance of the device. ()

According to CFR 807.87 the main requirements for premarket submission includes

• Name of the device along with the trade name and common name
• Registration number
• Device classification
• Device performance standards
• Device labeling along with its intended and indications for use
• A statement representing whether the product is a new device, or already has a predicate device in the market
• A statement indicating that the device is safe and effective for use
• A disclosure statement
• A statement indicating that all the information provided is correct to the best
• Additional information is provided upon request of commissioner. This information has to be submitted within 90 days, before marketing the device. In case if they fail to provide the requested information within 30 days then the commissioner has the authority to withdraw the device.()

Guidance and standards:

Various guidance documents for medical devices include preclinical studies, clinical studies, standards, labeling criteria, specifications etc. “In 1986, FDA, Health and Welfare Canada, and Health and Social Services UK issued the Tripartite Biocompatibility Guidance for Medical Devices.” Based on these guidance’s, medical device manufacturers select suitable tests necessary to determine adverse events associated with the devices. International standards Organization (ISO) proposed standard for devices, that is ISO 10993. ()

Clinical studies:

According to subsection 513(i) of FDC clinical studies are included in 510(k) approval process. ()These are conducted to estimate the oxygen saturation under laboratory conditions. According to FDA these devices are nonsignificant risk devices and are subjected to abbreviated Investigational device exemptions as per 21 CFR 812.2(b). Although these are nonsignificant risk devices, studies involving human subjects require informed consent (21 CFR 50) and IRB approval (21 CFR 56). Clinical trials are conducted on ten healthy subjects to determine the safety and performance of the device for medical use. During these tests the Oximeter under study is compared with a co-oximeter to determine the oxygen saturation levels. Based on the results obtained we can determine the accuracy and the sensors that are used. ()

Biocompatibility studies:

These studies are generally conducted to determine the toxicities that may occur with the devices that are in contact with body. Therefore, these devices are to be evaluated to assure that the benefits outweigh risks. These tests include skin irritation, carcinogenicity, genotoxicity, sensitization etc. Depending upon the nature of devices and their uses some additional tests might be required. In order to determine the substantial equivalence it is not necessary to perform all tests, but only those tests that are mandatory to demonstrate substantial equivalence are sufficient. ()

Non-clinical tests:

Based on these studies we can determine how accurate the new device is, compared to predicate device. Bench tests are performed to determine that the new device meets all the required specifications as that of marketed device (Substantial equivalence). Based on the results the following standards were observed.

IEC 60601-1:2005 + CORR. 1 (2006) + CORR.2 (2007)- they comply with the general requirements of safety and performance

IEC 60601-1-2:2007- they comply with safety, performance and electromagnetic compatibility

ISO 80601-2-61:2011- Safety and performance of the device

ISO 9919: 2005- Safety and performance of the pulse oximeter device for medical use

ISO 10993-5: 2009- tests to determine in vitro cytotoxicity

ISO 10993-10: 2010- tests for skin sensitization and irritability.(). ()

Labeling:

According to 21 CFR 807.87(e) proper labeling must be give along with the intended use and Instructions for use. Labeling should also include specifications that apply for the device such as accuracy of blood oxygen saturation levels and pulse rate, alarm ranges and limits along with their storage conditions. If the device is reusable then instructions for its cleaning and sterilization should be clearly indicated in the label. Labeling should also include any complications that are associated with the use of device. ()

According to sections 531 through 542, Electronic Product Radiation Control Provisions of the FDC Act, all the regulations described for radiation emitting devices are given in 21 CFR 1000 through 1299. They describe the required standards, labeling criteria and reporting requirements. Manufacturers are required to submit the required product reports and annual reports. In case of any serious exposure of the device at any stage of its development or testing, manufacturers must immediately notify FDA. ()

This device is widely used in hospitals, clinics and at home. Its market has a significant decline between 2008-2009. But later on with the advancement in technology, need in elderly people an enactment of more reliable detection algorithms has led to its need and increase in marketing. ()

Oximeters that are manufactured or imported in United States are subjected to FDA Radiation-Emitting Electronic Device requirements. In order to market the product manufacturers are required to submit Product reports and annual reports to FDA. Medical device companies manufacturing this device from outside into U.S are required to appoint an U.S. Agent for Service of Process.()

Center for Device and Radiological Health (CDRH) is responsible for all clearance process and to implement premarketing and post-marketing requirements. CDRH is also responsible to ensure the safety and effectiveness of devices before marketing. Office of Device Evaluation plays major role in premarket submissions. Office of compliance is responsible for all the regulatory activities of medical devices. Office of Management Operations advises CDRH on all administration issues. There are many such other organizations such as Office of Communication, Education, and Radiation Programs, Office of In vitro Diagnostic Device Evaluation and Safety, Office of Science and Engineering Laboratories. ()

References:

CFR – Code of Federal Regulations Title 21,Subpart E–Premarket Notification Procedures. (2013, 06/01/2013). Retrieved May 2, 2014, from

Exhibit #9 510(k) Summary. (2013). Retrieved May 2, 2014, from

How to Buy Home Pulse Oximeter.). Retrieved May 2, 2014, from

Jonathan S. Kahan, Hogan & Hartson. Medical Device DEvelopment: Regulation and law: Barnett International.

Premarket Notification (510k). 01/03/2014). Retrieved May 3, 2014, from

Pulse Oximeters – Premarket Notification Submissions [510(k)s].). Retrieved May 2, 2014, from

Pulse Oximeters Market to Exceed US$575 Million by 2015, According to New Report by Global Industry Analysts, Inc. (2014). Retrieved May 3, 2014, from

Syring, Gary. (2003). FDA Regulation of Medical Devices. Retrieved May 4, 2014, from

Townsend, Dr.Neil. (2001). MEDICAL ELECTRONICS. from

U.S. FDA Oximeter Requirements.). Retrieved May 2, 2014, from

Use of International Standard ISO-10993, ‘Biological Evaluation of Medical Devices Part 1: Evaluation and Testing’ (Replaces #G87-1 #8294) (blue book memo)(Text Only). (1995, 05/03/2009). Retrieved May 2, 2014, from

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