To support the use and evaluate the reliability of the patient data, it is important to to collect and record data about the identity and operational status of the device that generated the observations. The Device resource is an important locus for such information. The information it generates for clinical and other purposes goes into other resources such as the Observation or Medication resource depending upon what the device does. To support device-related information about Communicating Medical Devices the Device resource needs to have elements that describe not only the basic information like the serial number, manufacturer name and model number, but information about the protocol, its version, its certification, the properties it has to perform its purposed tasks such as internal clocks, synchronization state, resolution, etc.
A software item like a data transformer or converter, or a clinical support algorithm, may be an independently deployed, managed and configured entity that contributes to patient care and needs to be documented just a surely as, say, a physical cardiac monitor. The FHIR Device resource can contain instance data such as version information and operational attributes. It can also represent the relationship of the software item to other device and information system components through reference linkages. This category includes software regardless of whether or not is regulated. Device resource instances documenting software items are important to traceability of data and analyzing adverse events, and so have important patient safety roles.
In the case of an infusion pump, while some actions are focused on the device (e.g., ordering to a room or maintaining the pump), the focus is as well on the medication while the device is used for administration. However, that separation is not always as clear and may be impacted by specific implementations. Regardless, the Medication resource should not be used to represent (implanted) devices, rather reference the relationship where an actual device needs to be tracked in addition to the medication. In some sense the Medication is analogous to the Observation generated by a Blood Pressure personal health device. The Observation resource contains the blood pressure values, units and the time stamp while the Device resource contains the manufacturer name, model number, serial number, firmware and hardware versions, exchange protocol information, any clock capabilities, etc.
Nearly all devices are assigned a string of characters to represent one or more identifiers or codes, which are usually printed or affixed to the device using either barcodes or RFIDs. The identifier or code can come from the manufacturer (for example, a 'serial number', 'reference number', or 'catalog number'), various institution and registries. Any of these identifiers or codes assigned to the device can and should be recorded in the device resource. However, there can there can be confusion where to represent them in the resource because codes and identifiers are represented in FHIR as semantically distinct elements and because organizations may conflate the term 'code' for an identifier or 'identifier' for a code in their names.
The identifier element is only intended for use when it's an actual identifier for a specific instance of a device. That would mean that each device would have a separate serial number and would be represented using this element - devices without serial numbers (for example, a box of syringes) would not. Concepts such as a reference number or catalog number or GTIN describe a code which represents a kind of device and are conveyed using the type element. Some sources of standard codes for devices and translations within type are listed below:
The DI of the UDI may be stored in a jurisdictional repository and used as the primary key to access other device information. For example, in the United States, the DI of the UDI is submitted in a device record to the Global Unique Device Identification Database (GUDID) . The UDI may identify an instance of a device uniquely (when the PI includes a serial number), or it may just identify the type of the device. The UDI is parsed into its constituent parts (DI, PI and other elements) by parsing rules developed by each Issuing Agency standard. Where the device has an assigned UDI, the other details carried in the resource (e.g., lot, expiration date, etc.) SHALL be consistent with the information encoded in the UDI string or registered in the local repository.
USB serial connected to B650 monitor USB port, has to be ATEN UC232A (Vendor ID 0x0557 is ATEN) monitor has drivers for that VID. -&-thunderbolt/usb-converters/uc232a/ and used with a DB9 null modem cable in turn connected to the USB serial of the laptop. Data output protocol format has to be S/5.
The ADS8332 is based on the same core and includes a unipolar 8-to-1 input mux. Both devices offer a high-speed, wide-voltage serial interface and are capable of daisy-chain operation when multiple converters are used.
A hardware random number generator typically consists of a transducer to convert some aspect of the physical phenomena to an electrical signal, an amplifier and other electronic circuitry to increase the amplitude of the random fluctuations to a measurable level, and some type of analog-to-digital converter to convert the output into a digital number, often a simple binary digit 0 or 1. By repeatedly sampling the randomly varying signal, a series of random numbers is obtained.
Unpredictable random numbers were first investigated in the context of gambling, and many randomizing devices such as dice, shuffling playing cards, and roulette wheels, were first developed for such use. Fairly produced random numbers are vital to electronic gambling and ways of creating them are sometimes regulated by governmental gaming commissions.
The results of a long run from the RAND machine, filtered and tested, were converted into a table, which was published in 1955 in the book A Million Random Digits with 100,000 Normal Deviates. The RAND table was a significant breakthrough in delivering random numbers because such a large and carefully prepared table had never before been available. It has been a useful source for simulations, modeling, and for deriving the arbitrary constants in cryptographic algorithms to demonstrate that the constants had not been selected maliciously. The block ciphers Khufu and Khafre are among the applications which use the RAND table. See: Nothing up my sleeve numbers.
However, with sufficient care, a system can be designed that produces cryptographically secure random numbers from the sources of randomness available in a modern computer. The basic design is to maintain an "entropy pool" of random bits that are assumed to be unknown to an attacker. New randomness is added whenever available (for example, when the user hits a key) and an estimate of the number of bits in the pool that cannot be known to an attacker is kept. Some of the strategies in use include:
It is very easy to misconstruct hardware or software devices which attempt to generate random numbers. Also, most 'break' silently, often producing decreasingly random numbers as they degrade. A physical example might be the rapidly decreasing radioactivity of the smoke detectors mentioned earlier, if this source were used directly. Failure modes in such devices are plentiful and are complicated, slow, and hard to detect. Methods that combine multiple sources of entropy are more robust.
Just as with other components of a cryptography system, a software random number generator should be designed to resist certain attacks. Defending against these attacks is difficult without a hardware entropy source. 2b1af7f3a8