August 16th, 2012

Life without a pulse…

Version 1.1 of FDA Part 820 – QSR for iPhone / iPad / iPod Touch Just Released

August 25th, 2010

Version 1.1 of the FDA QSR (Part 820) has been just released on 8/25/10.
This upgrade makes the application fully compatible with iOS4x.

Take the FDA QSR with you everywhere and keep it always handy in your iPhone, iPod Touch or iPad.

The app can be downloaded from iTunes. Click here to get it!


- Self-contained e-book format.

- Fully hyper-linked table of content, for quick and easy access to the information.

- Bookmark functionality.

- Adjustable font size.

New Video Series on Rapid Prototyping Technology

May 8th, 2010

The folks at GROWit, the rapid prototyping (RP) service bureau of choice for medcraft’s Objet Polyjet  technology needs, has started a video blog covering the RP machines and materials they offer.

To learn about Polyjet RP technology see their first episode below.

Patenting Genes

March 31st, 2010

chromosomesOn March 29th, a New York federal district court ruled in favor of overturning gene patents issued to the University of Utah and licensed to Myriad Genetics, Salt Lake City, UT,  for commercializing genetic tests for cancer risk.

With approximately 2,000 human genes already patented, this court ruling sets precedent on a legal IP practice that’s been controversial from the start: where exactly is the “invention” with a gene, which is, before anything, a  “fact of nature” as the late Michael Crichton described it. I understand patenting a diagnosis method or therapy taking advantage of  a gene characteristic or mutation, or the method of isolating a specific gene, but I still don’t get the rationale behind patenting the gene itself.

A cursory review of one of the patents involved in this case (patent # 5,710,001 ,”17Q-Linked Breast and Ovarian Cancer Susceptibility Gene” ) indicates to me that patent enforcement may become an issue. For example, patent 5,710,001 indicates that it covers the gene isolation methods, the use of the gene mutation in the diagnosis of predisposition of breast and ovarian cancer, and therapy of cancers containing mutations of the BR1 gene.

But the patent language also clearly indicates that a discovery, that of the  gene and its mutations, is involved:

“It is a discovery of the present invention that the BRCA1 locus which predisposes individuals to breast cancer and ovarian cancer, is a gene encoding a BRCA1 protein, which has been found to have no significant homology with known protein or DNA sequences. This gene is termed BRCA1 herein. It is a discovery of the present invention that mutations in the BRCA1 locus in the germline are indicative of a predisposition to breast cancer and ovarian cancer. Finally, it is a discovery of the present invention that somatic mutations in the BRCA1 locus are also associated with breast cancer, ovarian cancer and other cancers, which represents an indicator of these cancers or of the prognosis of these cancers. The mutational events of the BRCA1 locus can involve deletions, insertions and point mutations within the coding sequence and the non-coding sequence.”

A “discovery” is not an invention, and therefore cannot be protected by a patent, or can it?

This ruling will certainly have important impact in the genetic research world.

The patents involved:

5,710,001 “17q-linked breast and ovarian cancer susceptibility gene”

5,747,282 “17Q-linked breast and ovarian cancer susceptibility gene”

5,753,441 “170-linked breast and ovarian cancer susceptibility gene”

6,150,514 “14 Kilobase deletion in the promoter region of BRCA1 in a breast cancer family”

6,162,897 “17q-linked breast and ovarian cancer susceptibility gene”

Wall Street Journal article, “Court Shoots Down Patents on Two Human Gene Sequences”

Obamacare Makes No Engineering Sense (As If Common Sense Were Not Enough To Know It Doesn’t Make Sense At All)

March 18th, 2010

(c)2009 Investors Business Daily

The principal argument used by the left to justify the mammoth healthcare legislation being forced by the White House and the Congress majority is that approximately 46 million Americans, 15 percent of the population, have no health insurance and therefore do not receive appropriate medical care. This figure stems from reports issued by the Census Bureau and is based on monthly surveys with a sample size of N=50,000 (50,000 persons surveyed). The latest report (2008) can be found here.

The left asserts that an 85% coverage yield in the current American healthcare process is not good enough for the most advanced country in the planet. This could be definitely arguable if the “defect” rate of the coverage rate of our healthcare system process were indeed 15%. But it is not.

Figure 1 shows a breakdown estimate of the 46 million uninsured figure made by the Heritage Foundation based on its own and external research1. Different breakdowns can be found in other references but this is the one I found the most consistent as it dissects the figure in congruent and relevant categories.

Figure 1. The "46 million uninsured figure" disected. (c)2010 Victor Gamez
Figure 1. The “46 million uninsured figure” disected.

Another unreported fact is that the uninsured rate has been pretty much constant in the last twenty years despite three economic recesions. In other words, the process is stable. This can be seen clearly in figure 2, drawn directly from the Census Bureau report.

Figure 2. The process is stable.

Let’s be kind to the left by severely handicapping the breakdown figures above by assigning to each category a constant distribution using the numbers reported by Heritage as the distribution upper limit and their respective half as the lower limit. This means that in our model any number from Heritage’s down to half that number has the same probability of being true (for example, the number of uninsured people with income greater than $75,000 can be anywhere between 4.65 and 9.3 million, and any number inside this interval has the same probability of being true according to our model). These distributions are shown in figure 3.

Figure 3. Constant distributions assigned to the "46 million uninsured" breakdown figures calculated by Heritage. (c)2010 Victor Gamez

Running an Oracle Crystal BallTM simulation using the distributions assumed above reveals that the number of truly uninsured can lie between 8.53 and 24.59 million, with 16 to 17 million having the greatest probability of being “the true” figure (figure 4). Figure 5 presents the data in percents form: the truly uninsured may compose 2.78% to 8% of the U.S. population. 5% to 6% uninsured may be the rate with the highest probability of being true (figure 5). Not bad for a system as large, diverse and complex as it is the American society. But here’s the interesting part: 5% to 6% of the American population would still not be covered should the Senate version of the healthcare bill was enacted, according to estimates from the Congressional Budget Office2. Where is the process improvement with this legislation then?

Figure 4. Forecast of truly uninsured (in millions), under the current healthcare system. (c) 2010 Victor Gamez

Figure 5. Forecast of truly uninsured (percent) under current healthcare system. (c) 2010 Victor Gamez

So the process is stable and the yield is high. What’s a reasonable operations manager to do then to improve this process? Focus on cost reduction and throughput, of course.

Sadly, although plenty of cost reduction schemes have been proposed, none of them have been included or even considered by the House and Senate democrats. Thompson Reuters published an excellent research paper addressing changes that would have a dramatic impact in lowering healthcare costs.

What the White House and Congress democrats are trying to do with healthcare is like fully replacing a 95% – yield process with one that is unknown, untested and unvalidated (Massachusetts anyone?).  All this in an attempt to completely eliminate a 5% defect rate of a process that accounts for approximately 16% of the United States GDP.

I would immediately fire anyone trying to force something like this at my factory. We’ll have the opportunity to do just that this mid-term elections.

All charts and computer models produced with Crystal Ball (Oracle Corporation) by Victor Gamez


1. Heritage Foundation, http://www.heritage.org/Research/Reports/2007/08/The-Heritage-Foundation-Responds-to-Uninsured-Numbers-in-New-US-Census-Bureau-Report.

2. December 19, 2009 letter from Douglas Elmendorf, Director, Congressional Budget Office to Senate Majority Leader Harry Reid.

FDA QSR Now Available for the iPhone, iPod Touch and iPad

March 15th, 2010

qsr screen1medcrafts’ new iPhone / iPod Touch / iPad application, “Part 820-QSR”, launched today on Apple’s  iTunes App Store.

Now you can keep the complete text of Title 21 of the Code of Federal Regulation (CFR) – Part 820, Quality Systems Regulations (QSR) right in your pocket at all times in a high-tech, sleek format. Say goodbye to that little QSR book in your desk drawer!

App features:

- Self-contained e-book format.

- Fully hyper-linked table of content, for quick and easy access to the information.

- Bookmark functionality.

- Adjustable font size.

qsr screen3

qsr screen2

TRIZ in Practice

December 7th, 2009

The third annual “Pumps and Pipes” symposium was held on December 7, 2009 at the University of Houston.
The goal of these conferences is to have an exchange of ideas on ways to tackle  problems common to energy (oil) and cardiovascular engineering and research. Non-newtonian fluid characteristics,  occlusions and  imaging challenges are examples of problems shared by both fields. Concepts  implemented in the oil industry  may very well be applied in vascular disease management and vice versa.


(c)2009 Pumps & Pipes

This is a great example of TRIZ in action (in oversimplified terms, TRIZ is a technique in which solutions for engineering design problems in one field are sought in other different fields).

The Pumps & Pipes Symposium 2009 was organized by Exxon Mobil, The University of Houston and The Methodist DeBakey Heart and Vascular Center.

Event website: http://tlc2.uh.edu:9080/pumpsandpipes

Five Essential Rapid Prototyping Resins

November 15th, 2009

Advancements in rapid-prototyping (RP) technology come hand in hand with a multitude of RP material options for the medical device engineer.  Although this is definitely a good thing, the large number of alternatives  may risk selecting a material more expensive than necessary or worse, a material that does not fulfill project needs.
The five rapid-prototyping materials listed below have been selected based on my practical experience. They will do the job for the applications indicated and may very well be the only rapid-prototyping material selections you will ever need in your daily practice.

Accura 50 (3D Systems, Inc. Rock Hill, SC)

PCB nest for circuit board electrical testing designed by Victor Gamez and produced with the Accura 50 resin. (c)2009 Victor Gamez

Accura 50 is an SLA resin intended to simulate molded ABS parts.  It is capable of producing intricate parts with fine details, a very desirable capability when prototyping medical devices. The material is stable over time, has good electrical insulation and is machinable, so it can be used for fixturing applications, such as the circuit board tester nest shown. This makes it an excellent alternative to Delrin. Most rapid prototyping houses will be willing to tap holes after producing a part, a perfect solution for those SolidWorks models with “cosmetic threads”. Finish is smooth and comes in two colors, natural (whitish) and gray.
A cousin of Accura 50 worth mentioning is the clear Accura 60, which simulates polycarbonate.  Ideal for catheter hubs prototyping.

FullCure Vero and Tango Plus (Objet, Rehovot, Israel)

These two materials work amazingly well together when simulating overmolded parts.  FullCure Vero simulates hard plastic and comes with a choice of four colors, all with mechanical properties within the same range.  Resulting thin walls are not as robust as those obtained with  Accura 50, but wall thicknesses down to 0.5mm are possible without collapse. The Tango Plus material provides rubber-like characteristics. It has the softest durometer of the Tango line and is also translucent. Perfect for prototyping implantable silicone parts.

Overmolded housing prototype for an electronic implantable designed by Victor Gamez/medcrafts using the FullCure and Tango materials. Wireless charging functionality required thin-walled features, which were provided effectively by these materials.

Overmolded housing prototype for an electronic implantable designed by Victor Gamez using the FullCure and Tango materials. Wireless charging functionality required thin-walled features, which were provided effectively by these materials. (c) 2009 Victor Gamez

Silicone housing prototype designed by Victor Gamez / medcrafts for an electronic implantable.

Silicone housing prototype designed by Victor Gamez for an electronic implantable produced with Tango Plus. (c) 2009 Victor Gamez

wrist unit mockup

Mockup model of a clinical electronic device conceptualized by Victor Gamez using FDM-ABS. (c) 2009 Victor Gamez

FDM ABSP400 (Stratsys, Eden Prairie, MN)

Generally, FDM-produced parts have a surface finish which may not be as good as that obtained with SLA (“stair step” effect is more evident without additional post-processing). Standard resolution is also lower than SLA. Nevertheless, FDM is an ideal choice for product mockup models. FDM ABS parts can also be machined, making it possible to modify models quickly based on initial test results. FDM is also cheaper than SLA and Objet technologies.

Design Verification Vs. Design Validation: A Practical Example

November 7th, 2009
CoStar DES Stent (Copyright Johnson & Johnson)

CoStar DES Stent (Copyright Johnson & Johnson)

Typically a responsibility of a company’s Product Development and Quality groups, along with the Clinical group, in cases in which clinical evaluations are required, Design Verification & Validation (V&V) refers to the set of activities aimed at establishing, with a high degree of confidence, that a design:

a) Meets specifications set during the design phase (Verification).
b) Fulfill users’ needs (Validation).

As an example illustrating the difference between Verification & Validation, consider the first incarnation of Conor MedSystems’ drug eluting stent (DES), the CoStar®.

In 2007 Conor MedSystems’ abandoned U.S. commercialization work of this coronary stent due to its inferior performance in preventing in-stent restenosis during clinical trials1. In this specific case, the CoStar® stent may have met all Design Verification criteria, that is, the produced device met all product specifications such as size, stent recoil, drug dosimetry, stent surface finish, fatigue requirements; and probably had met all criteria for Design Validation up to the clinical trials stage. But the clinical trial, a key Design Validation activity according to the FDA guidance document for drug eluting stents, uncovered that the CoStar® did not perform better or at least equally than the FDA-approved TAXUS® stent (Boston Scientific Inc.). While the study did not identify safety issues, the CoStar failed the last stage of its validation process: clinical trial data did not indicate that the product would fulfill user’s needs as the stent could not prevent in-stent restenosis at least as effectively as other drug eluting stents already in the U.S. market.

CoStar V&V Score Card in this example:

Verification: PASSED

Validation: FAILED


1. http://www.medicalnewstoday.com/articles/70138.php “Conor Medsystems, LLC Reports COSTAR II Pivotal Drug-Eluting Stent Trial Conclusions”Article Date: 08 May 2007 – 0:00 PDT