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Hitachi Cable America

Medical Solutions FAQs

Hitachi Cable America Frequently Asked Questions
 

Q: What is a conductor/conductance?

A: A conductor, in a cable, is the central material that carries an electrical current typically generated by the flow of negative ions along the surface of the metal. A conductor provides conductance (the ease at which an electric field can flow). Conducting materials include metals, electrolytes, superconductors, semiconductors, plasmas and some non-metals such as graphite or polymers. Copper in particular has a high conductivity, so annealed copper is the international standard to which all other conductors are compared.

Carbon, silver, copper, annealed copper, gold and aluminum (in that order) are the best conductors and most commonly used materials in cabling. Silver is more costly but is often used at higher frequencies to mitigate skin effect losses. Aluminum wires are often used for low voltage distribution, such as buried cables and service drops and it is the most common metal used for high-voltage transmission lines, in combination with steel as structural reinforcement. [?]

Q: What is an Insulator?

A: Insulators are any materials whose internal electric charges do not flow freely and therefore resist the flow of current. Current likes to flow in materials that have electrons which can easily gain energy and freely move about (as in metals). Insulators are necessary to protect a circuit from a dead short to ground. There are many forms of insulation and each one carries their own dielectric constant, which is the material’s measured value of resisting flow and it’s capability of being polarized. A true dielectric is an insulative material in which the atoms are free to rearrange themselves and thus become polarize when in the presence of an electric field. This is how capacitors work. The dielectric insulation sandwiched between the plates encourages the negative particles to accumulate in the + end of the dielectric while the – charges are repelled from the - side of the dielectric, leaving only the positive charge on that plate.

Most insulators have a large band gap. This is the energy range in a solid where no electron states can exist. This gap occurs because the "valence" band containing the highest energy electrons is full, and a large energy separates one band from the next band above it. There is always some voltage (called the breakdown voltage) that gives electrons just enough energy to be excited into this next band. Once this voltage is exceeded the material ceases being an insulator, and the charge begins to pass through it.

The primary purpose of insulation in a cable is simply to prevent the wire from short circuiting while also sealing the conductor from the air and environment. [?]

Q: What’s a dielectric?

A: A dielectric material is an electrical insulator that becomes polarized (much like a permanent magnet) when an electric field is applied to it. A perfect dielectric would have essentially zero electrical conductance, thus only exhibiting the polarizing (displacement) characteristics.

Dielectrics are used to support/improve capacitive devices. Unlike a conductor, the electric charges do not flow through a dielectric material, since it is technically an insulator. Instead the molecules freely rearrange themselves in a highly structured order (i.e. all positives and negatives facing the same directions). This acts as a ‘useful aid’ to the conductive plates by amplifying the repulsion of negative charges. The net result is a plate on one side with a surplus of negative charges (all packed in tightly). These are attracted to the positive charges of the dielectric and a deficit of electrical charges are formed on the opposing plate due to the dielectrics negative repulsive force, resulting a net positive charge on that plate. An excellent example of this can be found online at: https://www.youtube.com/watch?time_continue=460&v=f_MZNsEqyQw

A perfect dielectric constant has a value of 1. Not zero but 1, go figure! So, any material that is fully resistant to energy therefore has a dielectric constant of 1. The only thing that meets this requirement is a vacuum because a vacuum has no material, it’s a vacuum. Therefore, air which is clean and the closes you can get to a vacuum has the lowest dielectric of 1.0006.

Next in line come the preferred cable insulations of choice. These are the three amigos, as they are infrequently called in the industry (i.e. the Teflon®’s). They have the lowest constant of all the plastics known today, barring any exotic materials reserved for government skunk-works applications. They are used not only because of their low dielectric but also because they are highly resistant to temperature and chemicals while being very stable at higher frequencies where other materials are not.

The Dielectric values are as follows:

  • Low Density or Expanded (PTFE) Polytetrafluoroethylene (at 1.3),
  • (PFA) Perfluoroalkoxy (at 2.0)
  • (PTFE) Polytetrafluoroethylene (at 2.05)
  • (FEP) Fluorinated Ethylene Propylene (at 2.1)
  • (PP) Polypropylene (at 2.2)
  • (PE) Polyethylene (at 2.25)
  • (PVC) Polyvinyl Chloride (at 3.18)
  • (PET) Polyester (at 3.3)
  • Kapton® (at 3.6) but Kapton® is not good for high humidity applications since it is highly effected by humidity (i.e. water).
  • (PU) Polyurethane (at 8.5)
  • Note: (Kapton is a registered trademark of E. I. du Pont de Nemours and Company and Teflon is a registered trademark of the Chemours Company.)
[?]

Q: What is Resistance? (Also referenced here are Voltage and Current)

A: Resistance (which is measured in Ohms) is the tendency of a material to resist (not prevent) the flow of an electrical current (which is measured in Amps). Electrical resistance is analogous to friction in a mechanical system. Friction, like resistance, converts energy to heat and dissipates it to the surrounding environment. Therefore, electrical resistance can sometimes be thought of as a braking or dampening mechanism for a circuit. And this is important because there is no true loss of energy. Instead the energy is converted and redirected. When enough current is impeded (i.e. resisted) this energy can even be converted directly into light which reduces the current flow. And this is precisely how a resistive wire in light bulb glows.

Several factors impact resistance. The nature of the material, its thickness and length, and the temperature all play a part. Resistance is naturally low in materials with high conductance, such as metals. Part of the reason for this is the strongly structured crystalline properties of metal and the ability for electrons to freely skip from the conduction band of one atom to the next, while encountering little resistance.

Conversely, it is high in materials that are insulators, such as plastic and rubber. However, not all highly structured materials have low resistance. If the structure is very uniform, but complex, then the electrons will still encounter numerous collisions making it more difficult for them to move through the material. Glass is similarly structured and as an insulator it has extremely high resistivity, but this is due primarily to the fact that there are virtually no free spaces to be occupied in their conduction bands that would allow electrons to move through them. They are too tightly packed.

So, in materials where the atomic structure is both well aligned to min. collisions and the electrons are loosely held, then there is less likelihood of the current flow electrons bumping into other atoms and creating resistance. In this case, we would say that the conductance is generally high, as is the case with metals and some liquids containing free ions. It is this “bumping” that creates disruption (aka resistance) and it is the “barricade-free multi-pathways” that encourage conductance.

Length therefore greatly affects resistance; the longer the length, the higher the resistance. Picture a material one atomic layer thick but incredibly long. There is only one pathway forward with lots of barrier bumps assuming this is a poor conductor. Now as the material is thicker, it frees up more pathways and it reduces the amount of barrier obstacles. So, thicker substances will generally have lower resistance and higher capacitance.

The so with this in mind, the longer a substance is, then there is more of a chance for increased “bumping” due to the obvious increase in overall atoms. The same is true of a substances thickness. The more of it there is, the more chance for resistance. But now imagine you are down South. It’s really hot and the heat makes you slow down and want nothing more than a tall glass of lemonade.

Well the same is true of our poor electrons. As the heat spikes from the barrier bumps and the material temperature increases so does the resistance. Those electrons just want a tall glass of lemonade. So materials with lower conductivity (i.e. high resistance) need higher voltage (or electromotive force) to get the job done and drive the electrons forward. And higher voltage means more power (aka a bigger battery or drive unit).

So this makes sense when looking at the definition of voltage. It is the amount of “potential energy” that electrons have relative to another point, usually called the "ground", which is defined as having a potential of 0 volts.

P = V x I = VI

Here, P is the power (measured in watts. Watts are equal to 1 joule per second of energy transfer), I is current (measured in Amps) and V is the voltage.

Thus Watts = Volts x Amps

A great analogy for this is by comparing it to a hose (i.e. the material (length/width) and a water tank that the hose is attached to. When the tank is full, there is more pressure on the column of water and the water comes out of the hose with greater force than when the tank is almost empty.

With electricity, if you increase the voltage (through a voltage stabilizer) (i.e. the water tank), you tend to send more current (i.e. water) through the resistive hose. And conversely, if the hose is bigger (i.e. the material is thicker and less resistive), then this has the same effect as delivering more water at a greater force than a thinner hose would. Everything is a tradeoff to find just the right mix of materials and properties that reduce cost and meet the performance needs.

The following formula sums it up nicely:

V = I x r = Ir

Here V is the voltage, ‘I’ is the flow of current in amps, and r is the resistance of the body.

So, voltage is the product of the amount of current flowing in a material and its resistance. In other words, current (amps) is the voltage divided by the resistance of the body. And Ohm’s Law states that R = V/I so if you know the voltage and current (which is already a factor of the resistance/conductance of a material), then you automatically know the resistance.

So is it current (amperage) or voltage that is dangerous? Well the answer is actually IT DEPENDS on the conditions. Why, well there is a couple of popular proverbs in electrical engineering worth repeating.

V will not kill you, but I will. And …

I will follow the path of least resistance.

Yet despite these truths Nikola Tesla, who invented AC current claimed that a few million volts of current could be sent through a body when the frequency is above 700Hz. Frequency is the speed at which the electrons are pumped in an AC circuit creating an alternating positive and negative waveform. DC (Direct current) has no frequency or wave form. It is a flat line constant and asynchronous signal, so the above proverbs are spot on. Nikola stated that anything over 700 Hz simply flowed over the body. Fascinating if true!

In fact, almost any voltage can be withstood as long as the person never makes a connection to ground so this is generally why V will not kill you. It is merely a potential. This is how birds sit on electrical wires. It is the ground (or connection to ground) that releases the voltage potential and allows the flow of electrical current.

In addition, the amount of time that a current is passing through your system is critical. A brief moment can sometimes be tolerated but too long and it is catastrophic. People have been struck by lightning, which can pass anything from 100 to 1000 amperes of current through the body, and they have survived. Remember, voltage is the “potential” that is standing still, while current (amperage) is the voltage now moving to ground and it is the voltage that determines the force of the amperage.

A good way to look at it is, voltage is the caliber of the bullet and the amperage is the bullet being fired. So, much like a bullet when the amperage passes through something, that object or substance creates resistance. And the more resistance it encounters the more damage it can do. If the force and heat generated are too strong and too sudden, then object could quite literally blow up. This is often seen when a tree is struck by lightning. Trees are poor conductors and great insulators, hence they have high resistance. A sudden large current flow due to the massive voltage drop to ground leaves the force of the energy wanting to go in all directions, so the tree explodes. A person on the other hand is a relatively good conductor of electricity and therefore they have less general resistance so surviving a lightning strike is possible.

But in general, when not floating in air, being struck by lightning, or being hit with a bullet, it is safe to assume that as the flow of the electrons increases, so does the risk of injury. If the voltage passing through our bodies is at a low rate of speed (i.e. low current/flow) then we barely feel a thing. But when they flow is at very high rate of speed due to an increased potential and sudden release, and then bad things happen. As long as the electric charges pass through your body at a rate that is less than 1/1000 of an ampere (or one milliamp), they're not dangerous. But any voltages over 45 volts can be deadly.

Generally it is believed that larger voltages will do more harm than smaller ones. But in reality it is the current that flows between the two points that is ultimately responsible for the Electric Shock. It is not the voltage per se but the actual flow itself leading to ground. As the voltage potential increases the outcome for a larger current flow also increases, especially if the resistance of the object remains constant. This is because of the above formula: V = IR, higher the voltage; stronger the punch.

So if the resistance of the material is sufficiently low (for example a human with wet feet or hands) then even a small amount of voltage can produce enough current to create a decent shock. There's no widely accepted standard for safety on this matter but it is safe to assume that anything beyond 40mA is dangerous.

The minimum current a human can feel depends on the current type (AC or DC) and the frequency (assuming AC).

In general for a normal 68 kg (150 lb.) human applying (AC at 60 hz):

1mA (mill Ampere) or (.001A) of current can be felt. This is perception level creating a slight tingling sensation. It can still be dangerous under certain conditions.

5mA of current can be disturbing or painful given ones tolerance level. An average individual can let go. However, strong involuntary reactions can lead to other injuries.

6mA - 16mA will cause a painful shock and a person will begin to lose muscle control. This is commonly referred to as the freezing current or “let-go” range.

17–99mA, will cause extreme pain, respiratory arrest, severe contractions and individuals cannot let go. Death is possible.

100mA – 2,000mA will trigger ventricular fibrillation (uneven, uncoordinated pumping of the heart.) Muscular contraction and nerve damage begin to occur. Death is likely.

> 2,000mA will cause cardiac arrest, internal organ damage, and severe burns. Death is almost certain.

Alternating current (AC) and Direct current (DC) have slightly different effects on the human body, but both are dangerous above a certain voltage. As the voltage increases our body resistance drops. Essentially the body is less immune to the force and time that it can withstand the force. In a sufficient enough amount of time, the current can quickly tear down the skin and create a more favorable low resistance pathway which allows the high current to pass unimpeded and increases the risk of death.

An average normal human (under * normal conditions) above the ground level can withstand a voltage of about 26V DC & 60 V AC since 1 DCV ≈ 2.23 ACV. * Normal conditions refers to resisted, dry skin, no direct earth contact, low amperage (around 10 mA) & normal functioning of body. Note that since the magnitude of AC is roughly 2 times that of DC, it is generally viewed that AC is more dangerous since more DC current (roughly two to four times greater) is required to induce the same harmful effects as AC. With DC it is comparatively easier to “let-go” of ‘live’ parts that have been gripped, which is contrary to popular belief and experimental evidence. And DC does not affect the heart as badly as AC due to the AC waveforms that trigger the disruption.

Think of this as well, a person can discharge on the order of 50,000V when they get zapped from a carpet or from touching furry clothes. But they don't feel much because of the very small current (flow) that occurred in a very short-burst of time as it discharged.

On the other hand, a person will get on heck of a painful shock if they touch 220/110V mains, because of the larger current. Either of these uninterrupted will almost certainly cause death. In general, voltages above 50V are capable of delivering enough current to kill providing the skin resistance at the time is low enough and there is a suitable return path. [?]

Q: What is impedance and why is it critical?

A: Understand first that Resistance is a concept used for DC (direct currents) whereas impedance is the AC (alternating current) equivalent. Electrical impedance is a measurement in (Ohms) of the total resistance that a conductor presents to the electrical current passing through it. It is different for AC vs DC. With a DC circuit the resistance (the magnitude) is the impedance. However, with an AC circuit the impedance takes into account both the resistance (the magnitude) and the phase of the AC. The phase is simply a measurement representing the position at a particular point in time (an instant) on the actual waveform cycle. So charting AC impedance will show highs and lows as the waveform changes. Another way to think of it is that impedance is a more general term for resistance that also includes reactance.

In other words, resistance is the opposition to a steady electric current. Pure resistance does not change with frequency, and typically the only time that just resistance is considered is with a pure DC (not changing) circuit.

Reactance, however, is a measure of the type of opposition to the AC electricity due to capacitance or inductance. And this opposition strongly varies with frequency. At low frequencies the impedance is largely a function of the conductor size, but at high frequencies, conductor size, insulation material and insulation thickness all affect the cable's impedance and ultimately the signal quality. This in addition to inductance and capacitance are critical factors that must be taken into account based on the input signaling.

Quoting the below article, “In order for a cable's characteristic impedance to make any difference in the way the signal passes through it, the cable must be at least a large fraction of a wavelength long for the particular frequency it is carrying. Most wires will have a speed of travel for AC current of 60 to 70 percent of the speed of light, or about 195 million meters per second. An audio frequency of 20,000 Hz has a wavelength of 9,750 meters, so a cable would have to be four or five *kilometers* long before it even began to have an effect on an audio frequency. That's why the characteristic impedance of audio interconnect cables is not something most of us have anything to worry about. Normal video signal rarely exceed 10 MHz. That's about 20 meters for a wavelength. Those frequencies are getting close to being high enough for the characteristic impedance to be a factor. High resolution computer video signals and fast digital signals easily exceed 100 MHz so the proper impedance matching is needed even in short cable runs.” Read more at:

http://www.epanorama.net/documents/wiring/cable_impedance.html

When designing a circuit, if the system is designed to be 100 Ohms, then the components both entering and exiting the circuit should be matched also at 100 Ohms. This is very a crucial element to a good design. If there is any mismatch, error-producing reflections are created at the location of the mismatch and this creates loss. In general, for high voltage, the perfect impedance is 60 ohms. For high power, the perfect impedance is 30 ohms. 50 Ohms is the overall industry standard that was set for most equipment and devices and 75 Ohms is preferable for high quality video.

As a reminder, in a high impedance cable, the capacitance (or ability to hold a charge) will be low. And likewise, in a low impedance cable the capacitance will be high. Why is this? Well in simplest terms, higher frequency => faster rise time => the need to fill up capacitor/cable more quickly => more charges needed => more current => more power. [?]

Q: What is Characteristic Impedance?

A: Understand first that Resistance is a concept used for DC (direct currents) whereas impedance is the AC (alternating current) equivalent. Electrical impedance is a measurement in (Ohms) of the total resistance that a conductor presents to the electrical current passing through it. It is different for AC vs DC. With a DC circuit the resistance (the magnitude) is the impedance. However, with an AC circuit the impedance takes into account both the resistance (the magnitude) and the phase of the AC. The phase is simply a measurement representing the position at a particular point in time (an instant) on the actual waveform cycle. So charting AC impedance will show highs and lows as the waveform changes. Another way to think of it is that impedance is a more general term for resistance that also includes reactance.

In other words, resistance is the opposition to a steady electric current. Pure resistance does not change with frequency, and typically the only time that just resistance is considered is with a pure DC (not changing) circuit.

Reactance, however, is a measure of the type of opposition to the AC electricity due to capacitance or inductance. And this opposition strongly varies with frequency. At low frequencies the impedance is largely a function of the conductor size, but at high frequencies, conductor size, insulation material and insulation thickness all affect the cable's impedance and ultimately the signal quality. This in addition to inductance and capacitance are critical factors that must be taken into account based on the input signaling.

Quoting the below article, “In order for a cable's characteristic impedance to make any difference in the way the signal passes through it, the cable must be at least a large fraction of a wavelength long for the particular frequency it is carrying. Most wires will have a speed of travel for AC current of 60 to 70 percent of the speed of light, or about 195 million meters per second. An audio frequency of 20,000 Hz has a wavelength of 9,750 meters, so a cable would have to be four or five *kilometers* long before it even began to have an effect on an audio frequency. That's why the characteristic impedance of audio interconnect cables is not something most of us have anything to worry about. Normal video signal rarely exceed 10 MHz. That's about 20 meters for a wavelength. Those frequencies are getting close to being high enough for the characteristic impedance to be a factor. High resolution computer video signals and fast digital signals easily exceed 100 MHz so the proper impedance matching is needed even in short cable runs.” Read more at:

http://www.epanorama.net/documents/wiring/cable_impedance.html

When designing a circuit, if the system is designed to be 100 Ohms, then the components both entering and exiting the circuit should be matched also at 100 Ohms. This is very a crucial element to a good design. If there is any mismatch, error-producing reflections are created at the location of the mismatch and this creates loss. In general, for high voltage, the perfect impedance is 60 ohms. For high power, the perfect impedance is 30 ohms. 50 Ohms is the overall industry standard that was set for most equipment and devices and 75 Ohms is preferable for high quality video.

As a reminder, in a high impedance cable, the capacitance (or ability to hold a charge) will be low. And likewise, in a low impedance cable the capacitance will be high. Why is this? Well in simplest terms, higher frequency => faster rise time => the need to fill up capacitor/cable more quickly => more charges needed => more current => more power. [?]

Q: What is Capacitance? Why is it so critical?

A: Simply put, capacitance is the ability for something to hold a charge. It is the result of a body coming in contact with an electric charge and a load that results in a closed circuit. The charges carrying current in conductors make capacitance between each other as well as other nearby objects. This effect is called as stray capacitance. In power transmission lines, the stray capacitance could occur between each line as well as between the lines and the earth, supporting structures, etc. Due to the large currents carried by them, these stray effect considerably affects power losses in power transmission lines.

In a cable, the capacitance is usually measured in picofarads per foot (pf/ft). This indicates just how much electrical energy the cable can store. Capacitance can be viewed as an intimate ongoing relationship between the conductor and the ground plane. Along with Direct Current Resistance (DCR) are both crucial, it is one of the primary causes of loss in a circuit.

All materials have some form of capacitance or ability to hold a charge and subsequently dissipate that charge. In a cable, this process all happens very quickly, in a matter of picoseconds. Some materials will hold a charge better than others but everything has some level of capacitance, typically referred to as self-capacitance. In electrical circuits, the term capacitance though is usually a reference to mutual capacitance which is the ability to hold a charge between two adjacent conductors, such as with the two parallel plates in a capacitor separated by a dielectric insulator.

As a voltage is applied to a conductor, the charge gradually builds until the full length of the conductor and cross-section (based on the frequency being delivered) is energized to that potential. This creates a delay in voltage reaching its full potential. This is called propagation delay.

For low speed circuits this delay has very little impact but for a high speed circuit, that uses high frequency pulses, the propagation delay caused by capacitive and resistive affects will cause a loss of signal. Sometimes this is done deliberately in order to filter a circuit but generally capacitance in a cable is not favorable. But because of the complexity of making a low capacitance cable the cost is often higher. So designers must make tradeoffs between cost and performance when it makes good sense to do so.

The higher the frequency, the greater the reactance caused by the capacitance and the greater the signal loss. In the music world, a lower cable capacitance provides a “richer” sound quality. There is more of the natural “brightness,” “presence,” or “bite” from the instrument that can reach the amplifier. The same is true with video. Better signals provide cleaner and richer results with reduced attenuation and an ability to carry that signal significantly longer distances without degradation.

So, high speed circuits favor high impedance cables (or circuit board traces) because the signal quality is cleaner and it is ideal for shorter runs but can be extended to longer “mid-range” reaches without incurring significant loss. Because the cable has high impedance, i.e. low capacitance, it is “reactive” enough to respond quickly to the higher frequency signals with limited degradation.

So too is true of a cable is designed to be high capacitance. It will by nature have low impedance but it will be better for moving large amounts of data where the signal is somewhat less sensitive or critical. It is also better for longer distance applications due to the reduced impedance not restricting the flow. See:

http://home.mira.net/~marcop/ciocahalf.htm

Good conductor materials and dielectrics (that closely match the dielectric value of air) are needed to improve the signaling. Heat also plays a critical role in the capacitance because heat increases the atomic energy of the electrons and protons which results in the potential for more internal collisions of electrons bombarding the protons along the length of the wire. This increases the wires resistance and creates increased propagation delays.

As a wire is charged, the current through the length of the wire varies due to the propagation delay, until it has reached its full voltage potential. But unlike a capacitor there is no maximum charge or off switch state. Instead the wire either stays at the full potential as in a DC circuit or it discharges and charges again with the pulsed waveforms of an AC circuit.

For a cable capacitance can be minimized by either:

  • Increasing the insulation wall thickness;
  • Decreasing the conductor diameter; or
  • Using insulation with a lower dielectric constant or a precisely formed foamed dielectric that leaves voids to mimic an air dielectric.

There are other ways of controlling the cable capacitance as well:

  • Using the appropriate damping to resist resonate frequencies from vibrating a cable. Braided Kevlar tightly squeezed between the jacket and shield provides an excellent ability to dampen the overall structure.
  • Using materials that are less permeable. Even though all materials leak using materials like PTFE, FEP or PFA can provide for excellent barriers with lower permeability.
  • Using the best conductor materials to avoid oxidation on the surface of the conductor. If you think about this, since the current flows primarily along the skin of the conductor at high frequencies, then having any oxidation on this surface will certainly affect the dielectric value. And everything except for Gold below will oxidize. Copper when it oxidizes actually has an insulating effect whereas tin and silver can form whiskers which will create capacitance discontinuities.

The most commonly used materials are:

  • Aluminum
  • Copper
  • Tin
  • Nickel
  • Silver
  • Gold - the “Gold Standard” if you can afford it!


• Metallurgy techniques that reduce oxide formation due to crystallization effects. [?]

Q: What is Inductance?

A: An inductor is an electronic component consisting simply of a coil of wire. If a constant electric current is running through the wire then this produces a magnetic field. If the current changes, so does the magnetic field. The unit of measurement for inductance is the henry (H), named after Joseph Henry, an American physicist who discovered it independently around the same time as the English physicist Michael Faraday did.

One single henry is the amount of inductance that is required to induce one volt of electromotive force when the current is changing at one ampere per second. There are three laws that are linked to inductance. These are:

  • Oersted’s Law: which states, that a constant electric current generates a magnetic field around the conductor.
  • Faraday’s Law: which states, that a changing magnetic field induces a current in a conductor.
  • Lenz’s Law: which states, that this induced current is in the opposite direction of the change in current that produced the magnetic field. This phenomenon is called self-inductance.
So what does this all mean and what is the benefit? Well, because the inductor changes its magnetic field in opposition to a current spike or current drop, it tends to maintain the current at its previous level, thereby resisting the change. This tends to maintain the current at a constant level. In other words, an inductor creates a kind of inertia within the current flow that resists rapid fluctuations in much the same way that a large body resists changes in its velocity.

One important application for inductors is that they tend to block high-frequency signals while letting lower-frequency oscillations pass. This is the opposite function of capacitors, which allow AC current to flow freely flow while blocking DC once the capacitor is charged. This is why DC capacitors are often used as low-pass or high-pass filters. If the circuit is an AC circuit and it is susceptible to DC noise (as would be the case with microphone inputs or connections between audio components), then a DC capacitor in series before the rest of the circuit will only allow AC signals through. This is known as circuit blocking. However, if a capacitor is placed between a signal and a ground, then it will prevent AC signals from passing. This is known as a DC decoupling circuit and they are used frequently to remove ripple voltages from DC power supplies so that they deliver cleaner voltage.

Thus, by combining the two components (i.e. capacitors and inductors) in any circuit, it is possible to selectively filter or generate oscillations of almost any desired frequency. However, modern circuitry rarely uses inductors anymore because they can achieve virtually all the same results with micro-circuits and capacitors. [?]

Q: What is Attenuation?

A: Attenuation is the sum of losses in the conductor and in the dielectric that determine the exponential loss occurring to a signal during a transmission in a cable. In other words, it is the gradual extinction of the energy through the transmission medium or a ratio that compares input power to output. It is measured in decibels per unit length, typically db/ft or db/m. Attenuation is highly effected by frequency. If a cable works well at low speed, then it may not with higher frequencies. The greater the attenuation in a circuit, then more signal will be lost. So lower attenuation cable is always better but it comes at a price. Designers must make tradeoffs between cost, availability and “good enough” designs that make sense for everyone.

However, not all attenuation is bad. In the medical realm ultrasound makes heavy use of attenuation to differentiate or characterize various structures in the human body. The attenuation is viewed as a reduction in amplitude of the ultrasound beam as a function of distance through the imaging medium.

Power (attenuation loss) can be lost in a variety of ways:

  • Conductive Resistive loss – (dominate at lower frequencies)
  • Dielectric loss – (dominate at higher frequencies)
  • Radiated loss – (important but less dominant than the two above)
  • Product usage and life – (attenuation increases with the life of the cable)
Conductive Loss: To reduce resistive loss it is desirable to lower the heat generated from the skin effects with smaller and higher frequency cables. This is often improved by stranding with center conductors using 7 smaller wires twisted together forming a larger single gauge wire. For higher speed cables, since the resistance increases with frequency, larger gauge wires are often required to lower the resistance impact.

Dielectric Loss: To reduce dielectric loss, which is seen also as dissipated heat, properly understanding the frequency running through the cable is critical. Knowing the frequency range, be it high or low, will aid in the dielectric selection. Please refer to the 48 AWG low-capacitance coax in our catalog which has been optimized for higher frequencies with lower attenuation all because of the dielectric.

Radiated Loss: To reduce radiated loss focus needs to be place on the proper shielding. Radiated loss is typically more from interference than from heat loss, although heat being generated from a high speed signal is still possible. So there are two scenarios that shielding minimizes. These are radiated power or received power. Signals radiated from a cable are not desirable if there are sensitive receivers nearby. Likewise, received power is not desirable if there is a highly sensitive signal running through the coax. To prevent this many shield techniques can be employed including single layer spiral shield, foil tape, braided shields, tape and spiral/or braid, double and even triple shields, all in addition to changing the wire pitch which can have the effect of improving the shield coverage.

Product usage and life: Attenuation can increase over the lifespan of a cable. The primary reason is flexing with very small radii and moisture intrusion. Flexing losses can arise from bending due to disruptions in the braid material and the type of braid employed. If the braid is bent, small gaps are opened and there is an opportunity for radiated or received loss. Too tight of a bend and the dielectric may also be affected from the non-uniformity generated.

Loss due to moisture can occur when the shielding is corroded or the dielectric absorbs water, some dielectric materials more than others. Also, the presence of plastictisers in the outer sheath can lead to degradation and moisture intrusion. In terms of shielding:

  • Bare copper braid – is the general standard.
  • Tinned copper braid – creates 20% greater loss than bare copper but is more stable over time.
  • Silver plated braids – have less loss than bare or tinned copper but are more expensive.
[?]

Q: What is Single Ended Signaling?

A: Single ended signaling is the result of using a single individual wire to transport a signal in a circuit. Capacitance is this case is encountered from the nearest ground plane as the wire is charged. This effect is called stray capacitance because it strays from the axis of the cable and seeks the nearest ground. This can greatly impact the signals but for most low speed, short length circuits it is of lesser concern. If the ground plane distance varies along the traversed length of the cable then the capacitance varies as the signal builds along the length. This will either degrade or completely impede the signal. However, in the case of coax, the nearest ground plane is the shield. Typically the shield is negative and the conductor is positive. This sort of configuration is called a differential pair. Since the geometry creates a perfect concentric distance between the capacitive plates (i.e. the conductor and the shield) then the overall affect is a controlled capacitance throughout the length of the run and it is far more impervious to stray capacitance. Single ended signals that encounter high capacitance will often end up looking more like “Saw-teeth” that a clear square wave. The same is true of differential signal which will exhibit eye patterns that are not as well defined. An excellent article can be found here on the subject. http://www.edn.com/design/test-and-measurement/4389368/Eye-Diagram-Basics-Reading-and-applying-eye-diagrams [?]

Q: What is Differential Signaling?

A: Differential signaling is a method used to reduce electromagnetic interference (EMI) from external sources such as other cables, devices and/or crosstalk between neighboring traces or wires. Coax, twisted pairs, twinax and circuit board traces often employ this technique. The receiving circuit responds to the electrical difference between the two signals rather than the difference between a single wire voltage and ground. The wave form instead of being single ended peaks and valleys (for example from zero volts to five volts and then back down again) will instead look like mirrored signals with an equal Positive and Negative charge opposite the ground plane (zero) reference. This enables circuits to use less voltage to create a signal which also enables higher frequencies and faster speed cables due to the reduced capacitance need. [?]

Q: What is Coaxial Cable?

A coaxial cable (often referred to as coax) is a common cable variety designed for providing clean and uninterrupted high speed signals that are isolated from external electromagnetic interference (EMI). This type of cabling is often used to conduct weak (low-amplitude) voltage signals, due to its excellent ability to shield such signals from external interference.

These cables are found in cable television, Broadband Ethernet applications, video equipment, medical applications, closed-circuit television, ham and commercial radio and microwave transmission and even undersea cable systems where long haul, high speed signaling, free from interference, is required.

Coaxial cable is designed to resemble a series of concentric layered rings of varying materials. The centermost point is the metallic conductor. This conductor can either be stranded or solid. The conductor is then coated with a dielectric insulator that isolates the conductor from the shield. The shield, which follows the dielectric layer, consists of a wrapped metallic spiral, a braided mesh of wire, or a metallic tape foil covering the insulation. Over the shield a final jacket is formed that acts as a protective barrier from moisture and other substances based on the material used.

Within a coaxial cable, the electricity flows freely through the conductor at lower speeds, but as the speed increases the electrical cross-section decreases. This means that at higher speeds the electrical signals flow closer to or even along the skin of the conductor. This is called the skin effect and it is a critical characteristic of high speed cables that require very low capacitance to keep the signals intact.

The underlying reason for this is that electrons can act as both particles and waves. This is called the Complementarity Principle. As high enough frequency the particles act as actual waves propagating more than the volts and amps being induced by the electromagnetic wave. In essence, the conductors become wave guides. So a coaxial cable, for instance, that has high capacitance will result in a higher resistance because of the decrease in cross section due to the thinner skin (or reduced area) in which the high speed signals can flow. Also, every conductor has a minute amount of series inductance associated with it. The impedance (resistance) of an inductor increases linearly with frequency. At low frequencies, this inductance has a negligible effect, but it becomes very significant at higher (GigaHz) frequencies and above. [?]

Q: What is a Shield?

A: A shield is an electrical barrier such as an aluminum/mylar tape or served wire that resides beneath the jacket of a cable or device. It provides both an electrical barrier as well as a mechanical benefit of strength and cable protection. The shield in the case of a coax is the inner layer that sits above the dielectric enabling the capacitive effect. It is traditionally a metalized PET tape or spiral served wire.

Shielding effectiveness is very complex to measure and depends on the data frequency within the cable, the shield design and the means in which the cable is used and abused. A shield may be very effective in one frequency range, but horrible in another. If certain design factors are not taken into account or the cable is used improperly then shielding will have an impact on the overall success of a design. [?]

Q: What is Ultrasound?

A: Ultrasound is the process of using sound to create an image of something internal that cannot typically be seen with the human eyes. Other common applications include cleaning, disinfecting/disintegration, humidifying, welding, sonochemistry, sonic weapons and wireless communication.

It is defined as sound frequencies greater than 20 kHz and in air the (at normal atmospheric pressure) the wavelengths are 1.9 cm or less. High-power applications of ultrasound often use frequencies between 20 kHz and a few hundred kHz and it has the ability to create rather intense effects. Above 10 watts per square centimeter, cavitation can be inducted in liquid media, and some applications might even use up to 1000 watts per square centimeter in order to induce chemical changes or produce significant effects by direct mechanical action, such as inactivating harmful microorganisms. [?]

Q: Why do we use AC vs DC?

A: The simplest answer is: Edison won the battle for delivering power to America. Overall, DC is a safer and better power source but AC makes much more sense due to the long distances that it can be propagated and the cost of implementing DC power stations. However, DC is still very commonly used and preferred for extra high power transmissions. [?]

Q: What are the jacket options for Hitachi microcoaxial cables?

A: PET tape with adhesive or PFA jacket options. [?]

Q: What is considered the gauge range of microcoaxial cables?

A: 36-50 AWG is the common range. Products smaller than 50 AWG will be achieved in the future. [?]

Q: Does Hitachi offer stranded or solid conductors for its microcoaxial cables?

A: Hitachi offers both stranded and solid coax. Please refer to our catalog online for more information on the range of offerings. http://www.hca.hitachi-cable.com/products/medical/HCA-Medical-Brochure.pdf [?]

Q: What is the performance benefit of high impedance microcoaxials versus low impedance microcoaxials?

A: High impedance (low capacitance) micro-coax is excellent for high-frequency applications that require very high resolution signals with reduced attenuation. Low capacitance products will come at a slight cost premium over the high capacitance counterparts given the added complexity of making these products and the exacting precision and materials needed to decrease/control the capacitance. The low impedance (high capacitance) product is excellent for larger volumes of data at lower speeds that carry more power and do not require ultra-fine sensitivity of the devices they are attached to. Please refer to our link on what is capacitance for more information and our online catalog: http://www.hca.hitachi-cable.com/products/medical/HCA-Medical-Brochure.pdf [?]

Q: What is a guidewire?

A: A guidewire is a highly specialized complex metal wire structure that is capable of being steered through the arteries and veins. The wire will often have varying degrees of rigidity and it is highly responsive to rotational movements so that it can be steered. Many of these devices use additional materials to improve the ease of entry and they also include radiopaque markers that can be seen during the catheterization procedure. The guidewire is steered to the point in the body at which the procedure needs to occur. It is used as a carrying wire for the delivery of a wide variety of catheters, stents and other interventional devices. Once the guide wire is inserted, the catheter is slid over the guide wire and pushed directly to the location required. The guidewire’s shape in the body naturally steers the catheter. Often internal catheter layers have a hard and lubricious coating to support with inserting over the length of the wire. This is typical done with PTFE as a liner for the catheter. [?]

Q: What is a guidewire?

A: A guidewire is a highly specialized complex metal wire structure that is capable of being steered through the arteries and veins. The wire will often have varying degrees of rigidity and it is highly responsive to rotational movements so that it can be steered. Many of these devices use additional materials to improve the ease of entry and they also include radiopaque markers that can be seen during the catheterization procedure. The guidewire is steered to the point in the body at which the procedure needs to occur. It is used as a carrying wire for the delivery of a wide variety of catheters, stents and other interventional devices. Once the guide wire is inserted, the catheter is slid over the guide wire and pushed directly to the location required. The guidewire’s shape in the body naturally steers the catheter. Often internal catheter layers have a hard and lubricious coating to support with inserting over the length of the wire. This is typical done with PTFE as a liner for the catheter. [?]

Q: What is catheterization?

A: Catheterization is a procedure used to diagnose and treat particular conditions. Cardiac catheterization, in particular involves inserting an extruded catheter into an artery or vein in the groin, neck or arm and then, via a guidewire, steering it through the blood vessels to the heart. The process is used for sensing, diagnostics and treatments of a wide variety of conditions. The process is done in a cath lab typically under fluoroscopy. [?]

Q: What types of catheter guidewire coatings are there?

A: Hydrophilic coating - meant to act like a lubricant providing for more gentle navigation and good trackability
Anti-thrombogenic / Heparin coating - Designed to inhibit clotting
Hydrophobic coating - Used to enhance the users tactile response, resulting in a product that feels more responsive during surgical maneuvers
Silicone coating - designed to reduces friction
Tetrafluoroethylene (TFE) coating - Also designed to reduces friction [?]

Q: What are some common catheter types?

A: Indwelling Catheters - Stays in the body for a longer period of time
Intermittent Catheters - Used for a very brief period and purpose
Intravenous (IV) Catheters - Used to draw blood and provide fluids
Procedural Introducer Sheath / Dilators / Port Catheters - Access catheters for other procedures
Guide Catheters - Used to provide support for procedural device advancement
Delivery Catheters - Used to deliver fluids and chemicals
Diagnostic Catheters - Used to access key body functions and determine procedural needs
Procedural Catheters - Used to correct a problem within the body
Drainage Catheter - Used to remove fluids
Monitoring Catheters - Used to assess patients vitals and other ongoing diagnostics
Implantable Catheters - Catheters left in the body for long periods of time for the delivery of drugs, chemicals and accessing the blood
Hemodialysis Catheters - Designed specifically for the transport of blood during a transfusion. [?]

Q: How are catheters typically manufactured?

A: A medical catheter is manufactured in a clean room environment using precision medical grade extrusion equipment. Plastic pellets are fed into a hopper. The pellets enter a screw head where they are pressurized and melted. The screw head drives the molten material forward into the extrusion die that contains the shape of the internal and external tube profiles. Air and vacuum chambers are often used to assist in the flow of the material as it leaves the die. A puller then moves the material forward so it can momentarily air cool until it enters the water bath which finishes the cooling process. A tubes profile when it leaves the die is larger than the desired finished catheter. The material naturally stretches as it cools and is pulled. This 'drawn down' process will result in the desired end catheter size and diameter. Inline automated inspection equipment verifies the products dimensional characteristics and then the tubes are cut to length for annealing, secondary operations or direct packaging. [?]

Q: What characteristics are important in a catheter?

A: Every catheter style is different and the performance requirements are primarily based on the end application. In general there are several things to consider when designing a catheter. These are: Size, number of lumens, number of layers, the profile of the catheter and the lumens, flexibility vs. stiffness, responsiveness to torque, bondability, chemical resistance, lubricious needs, kink-resistance, wall strength, radiopaque characteristics, ability to be marked and printed upon, thermoplastic selection (choosing the right material for the complex requirement), thermoplastic availability (strongly tied to cost), thermoplastic color, thermoplastic purity, elongation characteristics, elongation memory (i.e. does it stay stretched), thermoplastic bio-additives or coatings, durometer and durometer changes, as well as tapering and bump transitions. [?]

Q: What is PTFE and why is it used for many catheter or medical applications?

A: PTFE is a synthetic fluoropolymer, well known due to the DuPont brand name, Teflon. PTFE has a very low coefficient of friction and high resistance to chemicals. However, it exhibits kink memory and a high incidence of thrombosis, making it unsuitable for long-term applications. PTFE is used in catheters because it has good lubricity, biocompatibility and chemical-resistance properties. PTFE is used in a variety of situations including diagnostic, guiding, suction, electrophysiology and neuroradiology. Additionally, they are used as stent delivery systems and transmyocardial laser revascularization (TMR). [?]

Q: What are radiopaque materials used for?

A: Radiopaque materials are used within medical catheters so that the device can be easily seen on X-ray film and under fluoroscopy in a radiology lab in order to provide medical practitioners with the ability to precisely position the device inside the body. The type and amount of radiopaque filler compounded with the thermoplastic material of the catheter, determines how they appear on screen. The filler affects the degree of contrast and the sharpness of the image because it influences the attenuation of X-rays passing through the body and the device. [?]

Q: What is durometer, flexural modulus and tensile strength?

A: Durometer is the measure of hardness for a material. Shore and Rockwell Durometer measure the resistance of plastics toward indentation. The higher the number the harder the material will be. Shore Hardness uses two different scales; Shore A or Shore D. Shore A is usually used for flexible materials and Shore D is used for semi-flexible materials. For catheters the durometer can vary from very stiff for maximum pushability to very flexible and soft for areas where invasive pushing could create damage. Durometer is important not only for the device in use but also for the manufacturing of the device. Some materials extrude better with particular zones of hardness.

Flexural modulus is the measure of a material’s bending stress relative to elongation under load. It provides an elastic measure of a material’s stiffness for a given test specimen and shape. The rigidity of a polymer tube is determined by the inherent stiffness of the material (modulus) and the cross sectional design of the catheter. Changing the dimensions of the cross section can have a profound impact on rigidity. Tensile strength is the maximum stress that a material can withstand while being stretched or pulled before breaking. This is important to understand for extruding thin walled tubes as well as for the tube’s performance. Heat shrink, balloons, and high pressure braided tubing all rely heavily on the tensile strength characteristics of a material. Materials such as Polyimide and PEEK have the highest burst pressure performance of materials commonly used in vascular catheters. To improve these characteristics, tubes are often braided to add strength and reinforcement to the structure. [?]

Q: When is etching of a catheter required?

A: All catheters at some point are taken from a simple extruded tube and made into a complete assembly. These final assemblies can contain any number of secondary operations and molded attachments that meant to be bonded/sealed to the surface of the catheter, whether thermally or chemically. Fluoropolymers are notorious known for their lack of bondability due to internal covalent carbon-fluorine bonds that make up the material structure. In order to create adhesion, some of these bonds need to be removed. This process is typically done with a chemical etchant that removes a very thin layer of the material, altering the atomic structure at the surface, and making the material more susceptible to adhesion. Etching is also useful for areas that require printing or marking on surfaces that would be otherwise resistant to adhesion. [?]

Q: What is a coextrusion?

A: A co-extrusion is a multi-layer extrusion. An initial tube is extruded and then a second tube is extruded over the existing tube. Often these materials are compatible so that the outer tube mechanically bonds to the inner tube. When the materials are not compatible, a tie layer is often required. This tie layer serves the purpose of bonding the outermost layer to the tie layer and then the innermost layer to the tie layer. This construction allows engineers to create unique structures that mechanically function differently inside and out. [?]

Q: What is a tapered tube?

A: It is very common for catheters to have a smaller diameter at the distal end and a larger diameter on the proximal end. The smaller end enables the operator to position the catheter into deep small internal veins of the body without doing any damage. The larger proximal end allows the operator more material to push against and also better access for external devices and procedures. The tube along the length goes from a slow transition from the thicker section to a thinner section. In addition to this transition, designers may also use multiple durometers along the length which can also impact the stiffness and flexibility of the material. It is possible to have multiple tapered transitions along the length of a product. The process is not limited to only one transition. This is also frequently called bump tubing. It is used for vascular access catheters, delivery catheters, drainage catheters, endoscopy and urology devices and dialysis catheters. [?]

Q: What is a tapered tube?

A: It is very common for catheters to have a smaller diameter at the distal end and a larger diameter on the proximal end. The smaller end enables the operator to position the catheter into deep small internal veins of the body without doing any damage. The larger proximal end allows the operator more material to push against and also better access for external devices and procedures. The tube along the length goes from a slow transition from the thicker section to a thinner section. In addition to this transition, designers may also use multiple durometers along the length which can also impact the stiffness and flexibility of the material. It is possible to have multiple tapered transitions along the length of a product. The process is not limited to only one transition. This is also frequently called bump tubing. It is used for vascular access catheters, delivery catheters, drainage catheters, endoscopy and urology devices and dialysis catheters. [?]

Q: What is the purpose of braided tubing?

A: Braided tubing is used for a broad range of medical applications. Stent and valve delivery sheaths, guiding catheter sheaths, valved vascular access sheaths and contrast media injection. Braided tubing is designed to withstand the internal pressure from the air or fluid passing inside it. For catheters, high-pressure braided tubing is used significantly in the administration of contrast media injection. Contrast media is an agent required to make even the smallest branches of the blood vessels visible during angiography procedures. Angiography is the process of taking an X-ray of blood or lymph vessels, carried out after introduction of a radiopaque substance. Depending upon the materials and construction, tubing can be designed to withstand low pressure situations (of around 500 psi) and high pressure situations (around 1,500 psi). To manufacture a braided tube, a central core is initially extruded. That core is then braided with a Nylon, Kevlar, stainless steel or even Nitinol wire. The type of braid and the complexity of the pitch are dependent upon the overall strength and properties needed within the tube. Once the entire length of tubing has been braided, that same length of tubing is again extruded. This encapsulates the braid within the wall of the outer tube. The braided section acts as a structural support to maintain the wall geometry and resist swelling formed due to the pressurized material moving within the I.D. Typically once a material expands and swells it is not likely to return to its normal shape and is at risk of rupturing. The objective is to prevent this from occurring. If a tube were to break during a procedure it could be quite dangerous and costly to the hospital and the patient. Reinforced tubing reinforcing provides added kink resistance, column strength (to make it more pushable), and it also increases torque transmission when compared to non-reinforced tubing. Typical braiding capabilities range from .75 French (Fr) Outside Diameter (OD) to 32Fr, with wall thickness as low as 0.005”. [?]

Q: What is a balloon catheter?

A: Medical balloons are devices generally placed near the distal tip of a catheter that are inflated in order to occlude a vein during a surgical procedure. They are common in the placement and delivery of stents, the repair of occluded veins and pressure monitoring situations. The balloon is attached (bonded) to a catheter and inserted into the body uninflated until it reaches the delivery point at which time it is inflated and the procedure is completed. Once complete, the balloon is deflated and the catheter is removed. There is a very wide range of balloons shapes, sizes, and manufacturing techniques. Like braided tubing, balloon tubing must be designed to withstand the pressurized expansion without rupturing or deforming. [?]

Q: What are secondary operations in regards to catheter tubing?

A: Secondary operations are value added services performed on an extruded tube in order to make it more complex and useful than the initial extruded tube. Typically secondary operations are performed to create features and profiles that cannot be done practically and/or cost effectively using conventional extrusion techniques. Examples of this are, heat treating/annealing, hole drilling, skiving, punching, pad printing, shape forming, tipping, sealing, etching, welding, bonding, assembling marker bands, wire termination and overmolding. Secondary operations are often precursors to final device assembly in which the device is fully completed and placed into packaging trays for bulk sterilization. Many facilities that provide secondary operations also provide full device termination services since it is more cost effective than sending to another manufacturer to complete the work. [?]

Q: How are products sterilized?

A: Hitachi does not currently provide device sterilization. We do however manufacture all of our products in a 13485:2016 registered facility that has a class 8 clean room for secondary operations and assembly. In addition, we use medical grade materials and 13485 standard procedures that keep our operation clean and efficient. Many OEMs work directly with bulk sterilization services that manage only that aspect of the project. Because sterilization is so critical to providing a safe and reliable product to the hospitals and patients, this process is generally outsourced to a specialist or done within the hospital itself. The optimal sterilization process for a given device is determined by materials, shelf life, quality, and the application requirements of the device. Typical sterilization procedures are: Chemical wipe down, autoclave sterilization, Gamma (Cobalt 60 radiation) sterilization, EtO (ethylene oxide) sterilization and electron beam irradiated (E-Beam) sterilization. [?]

Q: What is a CE mark?

A: A CE mark is a European standard certification mark that indicates that a product is in conformity with health, safety, and environmental protection standards for any products sold within the European Economic Area (EEA). Many medical companies used to turn to Europe first for marketing their products since it was a much easier process to get through the regulations and hurdles as compared to the FDA. Recently however, the EU has been cracking down on the medical industry and they are making it much more restrictive. [?]

Q: What are the three types of medical device classes per the FDA?

A: Class I devices are minimum risk potential. They are regulated and controlled to the bare minimum possible extent. Some examples of Class I devices are elastic bandages, examination gloves, stethoscopes, and battery-powered ophthalmic electrolysis units.

Class I device manufacturers must:
Register their manufacturing facilities to ISO 13485 standards
Providing a list of marketed devices regularly to US Food and Drug Administration (or FDA)
Comply with Good Manufacturing Practices (GMP)
Maintaining records of any device malfunctions and resulting injuries caused by the device
Reporting any device removal or corrections
Submit a premarket notification to the FDA before marketing a product, unless the company has exemptions
Class II requires special controls. In addition to submitting a premarket notification, Class II devices must comply with the established performance standards to ensure safety and efficacy. Some examples of Class II devices are powered wheelchairs, infusion pumps, blood pressure monitors, and electrocardiographs. Most of the regulatory requirements are related to the following:
Construction or composition of the device
Device testing
Labeling requirements to ensure proper installation, use, and maintenance Post-market surveillance
Class III require Premarket approval (PMAs). These are medical devices that are life-sustaining, prevent impairment of health, present an unreasonable risk of injury or illness, and where general controls and performance standards are insufficient to ensure device safety and efficiency are classified as Class III devices. In addition to complying with the control requirements as applicable to Class I and Class II devices, Class III devices must obtain premarket approval before marketing the product. Some devices that establish substantial equivalence to pre-1976 legally marketed devices are not required to obtain premarket approval and can be marketed through the premarket notification process until the FDA publishes a PMA requirement for such devices. Some examples of Class III devices are implantable cardiac pacemakers, silicone gel-filled breast implants, and replacement heart valves. [?]

Q: What products does High Performance Medical Solutions make?

A: High Performance Medical Solutions offers a full suite of medical catheter tubing and braided tubing. We offer a broad range of value added secondary operations and catheter assembly services, including full device packaging. Along with tubing we also offer fine wire medical cable, bundled cable and cable / wired catheter assembly services. Our machine shop offers a broad range of machining services and complete component and equipment fabrication. We specialize in precision tools, dies and extrusion equipment for a wide variety of medical tubing providers and DOD applications. We also offer diverse specialty materials and research and development access through our parent company Hitachi Metals. [?]

Q: What is the High Performance Medical Solutions division specialty?

A: Hitachi has many specialties within the medical space. HPMS specializes in providing extremely hard to manufacture medical tubing suitable for intra vascular access (peripheral devices, PICCs, ports, dialysis, and central venous), cardiovascular (angiography, diagnostic mapping, ablation, IVUS, inflatable balloons and guiding catheters), urology, neurovascular applications, and specialty catheters. On the wire and cable end of the business, HPMS (Hitachi brand) is a world recognized leader in the ultrasound and fine wire space. We provide full contract manufacturing assembly services in Suzhou, China. We manufacture some of the smallest and most complex wire and devices in the industry (single wire, coaxial wire, small gauge twisted pairs, twinax cable, bundled cable and hybrid cable). Our parent company Hitachi Metals specializes in developing and manufacturing highly advanced materials for a wide range of industries and applications. [?]

Q: Do you offer finished device assembly / full device packaging?

A: Yes, we can provide value added services such as clean room secondary operations and full device assembly including packaging? If there is a need for wire and cable within a device, we also offer full cable assembly device termination. [?]

Q: Do you have Clean Room manufacturing?

A: Yes, we have an ISO Class 8 cleanroom and white room manufacturing. All of our secondary operations and device assembly is done within the ISO Class 8 cleanroom. [?]

Q: Do you have design capability?

A: Per FDA regulations (for catheter tubing and catheter assemblies) we are not certified to provide product designs for our customers. All customers must provide controlled drawings and specifications that we manufacture against and adhere to. We can provide design support and substantial feedback on various design selections, but final design ownership and end-product validation falls upon our customers. For medical cable we will provide design support services as needed. The customer must validate all cable specifications and provide acceptance to build against such specifications. They are the end owners of the design and product validation. [?]

Q: Are you ISO13485 registered?

A: We are ISO 13485:2016 certified [?]

Q: What is your lead time?

A: We take all lead times on a case by case basis based on complexity and value added requirements of the build. We will consider expedites upon request and capacity availability. [?]

Q: Do you manufacture your own extrusion tooling?

A: We have in-house manufacturing for all of our extrusion tooling. We even manufacture a large share of our own extrusion equipment and downstream extrusions support equipment. Our machine shop was put in place to support the medical business. They are very well versed in highly complex tubing and sophisticated material needs, which may impact the tooling design or equipment requirements. Because of our in-house services we are capable of doing multiple, quick-spin iterations of a project in order to dial in the exact tubing dimensions required. This access gives us a tremendous advantage when it comes to reducing development lead time and providing iterative design support for OEMs looking to experiment. [?]

Q: Do you offer local sales support?

A: We offer a full staff of local sales that covers North America as well as a global sales team that handles Europe, India, Asia and other regions of the world. [?]

Q: Are you certified to work with the DOD and Medical manufacturers?

A: Yes. We are ISO9001:2015 for Defense and Industrial work as well as ISO13485 certified for Medical applications. We are also ITAR and JCP registered. [?]

Q: What industries do you provide CNC machining and production machining for?

A: We proudly serve a variety of industries including but not limited to: Defense, Medical, Oil & Gas, Aviation, Pharmaceutical, & More. [?]

Q: Who are some of your Defense and Medical Customers?

A: For the privacy of our customers, we do not share customer information. This is especially important when dealing with ITAR compliance and customer confidentiality. Being situated in the North East in one of the major hot beds for DOD manufacturing activity as well as the Eastern hub for medical activity, we are proud to say that we serve some of the top OEMs and DOD providers worldwide. [?]

Q: Can you handle multiple-process manufacturing such as machining, anodizing, welding, fabrication and assembly?

A: Yes, we are a one stop Job Shop. We work in partnership with a variety of DOD and Medical contracting vendors that are ISO and NADCAP certified. No matter what the process is we have a solution that will meet your requirements. [?]

Q: Can you accept drawings electronically?

A: Yes, for rapid response quotes, please contact us. [?]

Q: What materials can Hitachi machine?

A: We work with many types of exotic metals. We regularly work with Nickel based alloys like Inconel and Monel, Titanium, Stainless Steels, Aluminum, plastics (i.e. Teflon, Delrin, Acetal, Add Hastelloy, CPM10V, Polycarbonate) and many more. [?]

Q: Do you provide low quantity or prototype machining services?

A: We do provide low quantity and prototype machining for products. This includes design verification services. [?]

Q: What is the maximum working envelope dimensions that the shop can handle?

A: We have mills that are capable of cutting parts the size of 40” x 26” x 25” (X,Y,Z) and Lathes capable of turning parts up to 26” diameter. [?]

Q: Can blanket orders be established with multiple releases and shipment dates?

A: Yes, we can setup your orders to ship as needed and we can accommodate blanket orders and releases. [?]

Q: For tight tolerance work, how do you ensure perfect quality every time?

A: We perform a standard 100% CMM inspection on all parts leaving the shop. We use an optical vision measuring system that is both non-contact and contact when desired. The equipment is capable of high volume data calculations, and data retention. We can track any build by lot code and operator. [?]

Q: What is a catheter?

A: A catheter is a medical term for a thin walled single or multi-lumen tube that is typically used for medical procedures or devices which diagnose and support in restoring the health of an individual. The tubes are typically small enough to be inserted through the arteries and veins within a body and are often designed to have many unique properties that support the required procedure. Catheters can be used for introducing fluids, drugs or antibiotics, draining fluids, introducing secondary catheters and surgical devices or as coverings to specialty instruments. [?]

Q: What is the catheter French scale?

A: The French Scale is a unit of measure to help determine the circumference of a catheter. 1 French is equal to 1/3 of a millimeter; 3 Fr = 3 mm circumference and approximately 1 mm diameter. [?]

Q: What are some common radiopaque fillers?

A: There are a wide variety of radiopaque fillers. These are barium sulfate, bismuth subcarbonate, blend of barium and bismuth, bismuth trioxide, bismuth oxychloride, tungsten, platinum and other proprietary blends such as platinum and iridium. Barium sulfate is by far the most common and cost effective. [?]

Q: What is biocompatibility?

A: Biocompatibility is the measure of a materials compatibility with the body, be it animal or human. For a product to be biocompatible it must not decompose or put off contaminants that adversely affect the functioning or comfort of the body (either short term or long). Things that require biocompatibility testing are materials which will be implanted or in direct contact with the blood and tissue. Bone implants, heart implants, catheters, diagnostic fluids, external cables, gels and adhesives are all examples of this. [?]

Q: What is a 510(k)?

A: A 510(k) is a Premarket Approval application submitted to the FDA for anyone who wants to market a medical Class I, II, or III medical device intended for human use in the United States of America. Typically, products are designed, tested and planned for production, but are never launched until the 510(k) approval is received. This process, depending upon the complexity of the device, can take anywhere from just under a year at best to several years depending upon the class of the device and testing required to ensure that the product is safe. Even once a 510(k) is received, OEMs must still provide data and monitoring information to ensure that the products are being manufactured and distributed in accordance with the original filings. Any deviations from this process can trigger the FDA to immediately pull a product off the shelves. OEMs take the medical regulations and monitoring very seriously since the impact of a recall or a product failure can be quite substantial. The FDA has the authority to ban or limit the use of certain devices that violate the medical device amendments and provisions in the FD&C Act or present an unreasonable risk of injury. [?]

Q: What materials do you extrude (or not extrude)?

A: We provide a very broad range of industry standard medical materials. We work closely with compounding partners that can offer specialty additives and blends for altering existing material properties. We extrude a large quantity of thermoplastic and polyurethane tubing as well as hard to extrude materials. For a deeper look at our materials please refer to our catalog. [?]
 
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