There are number of medical device which are used outside the body. For instance, we can even take glucometer. It is a device used outside the body only to measure the glucose level in blood. Verification and validation is necessary for this device. When device is not used inside the body or invasive most of the time clinical trial won't be a necessary one. Most of them fall under class 1 category.

The only medical devices used outside the body that likely wouldn't need clinical trials are probably low risk devices where there are already substantially equivalent devices on the market such as gauze, stretchers, walkers, surgical masks, stethoscope, or a gait analyzer.

Devices which are used outside the body and which does not need clinical/ preclinical trials does not possess severe risks to patient. Few examples include sthethoscope, surgical tape, colostomy bags etc. These devices does not pose risks to patients and only verification and validation is sufficient rather than preclinical/clinical trials.

There are bunch of medical device that does not need clinical trial. Anything that has external use usually does not need medical device such as stretcher, medical gloves, assistive cane, walker, and other bunch of them.

Devices which are used outside the body and which does not need clinical/ preclinical trials does not possess severe risks to patient. Few examples include sthethoscope, surgical tape, colostomy bags etc. These devices does not pose risks to patients and only verification and validation is sufficient rather than preclinical/clinical trials.

Device like thermometer, gauze piece, micropores are used outside the body. Only verification and validation is sufficient for these devices and clinical/preclinical trials are not needed. These devices are low risk devices which does not harm patients.

If there is sufficient evidence already available for a similar device, V&V will only be necessary to make sure that the device meets the user needs (validation) and that the device functions as it should (verification). However, sometimes the results from clinical trials may be necessary for design verification. In this case it would be helpful to keep in mind how a certain user need will be met when the user needs are created. With proper documentation and planning, the devices that have been mentioned should not require clinical trials.

Glove liners or under gloves are worn with patient examination or surgeon’s gloves which are made of material such as cotton to prevent the medical glove from contacting the user’s hand or may be made of the material that are resistant to cutting or puncture. Medical devices such as crutch which is used as a mobility aid that transfers weight from the legs to the upper body. It is often used by people who cannot use their legs to support their weight.

The purpose behind pre-clinical and clinical trials is to determine how a product or service performs on a group of test subjects. Without clinical trials, there will be no way to determine the efficacy of the product or if the desired result is reproducible and causes arm to some patients. Products and services that do not cause harm to patients( e.g. thermometer) do require clinical trials to determine the efficacy of the product. This would only require Design Verification and Validation since you are trying to ensure that the instrument works. You want to make sure that there is no internal/external problem with the thermometer so that it will work in every case that it is relied upon.

As pointed out by Dr. Simon if a medical device is a component and not directly used by the patient then the user needs and the specifications are essentially the same thing and design validation is not necessary for that product. This kind of confused me because I thought about diagnostic or prognostic testing; this is something that is not utilized by the patient, but is instead used by the physician providing care for the patient and any diagnostic test needs validations and verification studies even if they have 510k clearance and there is something similar in the market already. Could someone perhaps shine some light on this issue? Maybe I misunderstood the question? 

I agree with them not needed clinical trials since they are not directly used on the patient, but do think they need long validation studies and correlation studies with already existing devices. 

None of class 1 and even many class2 devices are exempted from clinical or preclinical studies, although they require design controls and other specifications. Since they do not directly react with the tissues diffusing chemicals or modifying the structure/mechanism, they usually are safe to use. Examples- Wheelchairs, Pulse oximeters

I believe only conducting verification and validation studies is acceptable for a class I medical device or a class II medical device that is substantially equivalent to an existing product and requires just a 510(k) without pre-clinical and clinical trials. I am under the impression that any product that can pose moderate risk such as a diagnostic to detect diseases or guide treatment decisions as well as medical devices that are a combination product and require specific drug dosing, as per the examples in question from this thread, would require clinical trials in order to obtain premarket approval. Although there may be evidence of an existing use case, the manufacturers must still demonstrate their application/technology is similar, safe and effective, and has clearly indications for use which would require pre-clinical and/or clinical studies.

I think that devices that aren't going to be invasive to the user, Design Verification and Validation would be enough. I would say for Clinical Trials are unavoidable though they would be implemented for clarification. Such devices like blood pressure machines, compression socks, and thermometers would fall into this category.

The Design and Development phase typically follows a Project Planning phase. According to the FDA,  design verification is confirmation by examination and provision of evidence that requirements are fulfilled. Pre-clinical’s role in a new technology is to journey with the design and development phase to assure the product is fully dependent on itself.  At the completion of project planning, innovators will know what is required to move from prototype to product. The meat of the job is superbly completing the design tasks, and ensuring that the device is ready for safe and effective customer use.