About Medaval & Accurate Devices

Incorporated in 1989 as Medical Device Assessment Ltd, the company abbreviated its name to Medaval (med-a-val) in 2015. The purpose of the site is to provide, for all purchasers of medical devices, an identifiable mark, the Medaval Certificate of Accreditation and its logo, indicating proven measurement accuracy to current standards.

Users of medical devices, and potential purchasers, can check their measurement accuracy, from the most accurate, with Medaval certification, to those that have never had their accuracy checked properly or at all.

Health care professionals, patients and consumers are cautioned against using any medical device that has not been tested correctly for accuracy.

Medaval Site Description


The site provides, for the first time, a comprehensive resource for information on medical devices that will provide the user, whether a health professional or lay patient, with an up-to-date assessment of the accuracy and quality of all devices providing measurements or indices of health and disease. As a first step, Medaval completed a comprehensive survey of blood pressure monitors, blood glucose meters and pulse oximeters available on the market. In assessing the many thousands of devices available, the following procedures were carried out and are now posted on the Medaval website:

Listing of devices on the market

Devices on the market were identified, together with manufacturer details, user manuals and all published evidence of performance and accuracy. Details for over 2,200 blood pressure devices, over 550 blood glucose monitors and over 100 pulse oximeters are posted on the Medaval website and are available for scrutiny.

Listing of devices with validation studies

Devices, with measurement technology for which a scientific validation study was carried out, were identified and listed separately from those for which it was not possible to find evidence for a reported validation study. Only 391 of the 2,244 blood pressure monitors (17%) and 50 of the 559 blood glucose meters (9%) were identified as having a published validation (as listed in PubMed), of the respective measurement technology, according to a recognised standard protocol. We were unable to find any such validations for pulse oximeters.

Lists of validated devices, divided into categories, including validations in special populations, are provided under the Approved Lists tab.

Certification by Medaval

Medaval certification is awarded only to devices with the most accurate measurement technology. The first consideration is the validation protocol. Medaval insists that only the most recent standard protocols are used. Older protocols are not recognised for certification, as their requirements, having been superseded, do not meet current standards. In general, technological advances allow error margins to be narrowed over time while, at the same time, clinical research also drives a demand for increased accuracy. Similarly, ad-hoc protocols are not recognised. While they have a role in the development of new standard protocols, the reliability of the results has yet to be proven.

The passing criteria in validation protocols are based on specific sample distributions and on other criteria and can only be applied if all of the instructions are followed correctly. Therefore, in any validation study, Medaval, first tests the hypothesis that the study was not carried out in accordance with the requirements and it is only if that hypothesis is rejected can the results be considered reliable.

As many validation studies have been published despite the fact that the protocols used were not followed properly, Medaval insists on scrutinising all validation studies from scratch to ensure that a suitable protocol, meeting current standards, was used to ensure that the protocol was followed correctly and to ensure that the measurement technology satisfied the passing criteria. Only when these criteria are satisfied, and the results checked by members of the Medaval Review Panel, can devices using this technology be certified.

However, Medaval does recognise that many devices have been validated over the years, often using protocols which were the most recent at that time. As such, where devices have passed a standard protocol, with the results published in a recognised peer-reviewed journal, these, and other devices proven to use the same measurement technology, are listed, as validated, on the website.

Many devices have never been subjected to a validation study and some manufactures appear reluctant to have any of their devices validated. Health care professionals, patients and consumers are cautioned against using any medical device that has not been tested correctly for accuracy.