SOTERA WIRELESS ViSi MOBILE SYSTEM

The Sotera Wireless Vital Signs Mobile system continuously monitors patient vital signs, including pulse rate (PR), heart rate (HR), respiration rate (RR), NIBP, and pulse oximetry (SpO₂), as well as level of motion on adult patients in inpatient lower-acuity care settings. Continuous noninvasive blood pressure (cNIBP) is achieved by taking a baseline measurement with a standard NIBP cuff and then using pulse arrival time to estimate changes from baseline. The system analyzes and interprets vital signs data to alert clinicians to emergent events like high HR or low SpO₂. The system also displays trending data to help clinicians detect early signs of patient deterioration. 

This system offers optional 3- or 5-lead ECG for monitoring purposes (i.e., not diagnostic, and no arrhythmia detection). 

 Central workstation is available and allows control of system for up to 32 patients at a time. Just like the cetntral monitors in the ICU, it can used to:



- Admit and discharge patients
- View graphical and list trends for 3- or 5-lead ECG, SpO₂, temperature, PR, and RR
- View real-time data, including visible and audible alerts and alarms
- Communicate to secondary alarm notification systems or middleware for clinician notification
- Send patient vitals data and alarms to patient electronic medical record (EMR) via an HL7 (Health    
  Level 7) interface.

Remote viewing screen is available for viewing of near-real-time patient data, trending information, and alerts/alarms through WLAN, etc.



The Sotera Wireless Vital Signs Mobile system is a good choice for low-acuity continuous vital signs monitoring applications on a medical-surgical floor. The system has simple patient setup. Trending information is potentially helpful to detect patient deterioration. 
The use of continuous noninvasive blood pressure (cNIBP) is impressive and potentially much more comfortable for the patient than periodic NIBP cuff inflation. Sotera provides the widest variety of alerts for emergent events and status changes. This system is not designed to provide trend alerts or early warning scoring. It is probably best suited to sick patients who need constant monitoring and alerting for emergent events. Battery life is short; two wrist units are required per bed for 24-hour coverage.

System components of the Sotera ViSi Mobile System

Information on this page is provided for interest only on a "best efforts" basis and does not 
constitute personal advice. Always discuss medical conditions and related matters with your doctor.
 
Source: ecri institute

Real Time Location System (RTLS)

I thought I write about the system which is really not a biomedical instrumentation but it helps to manage asset by tracking equipment location with ease by locating them during periodic maintenance or in times of clinical needs for the patients where equipment are needed from the various available locations. It can also manage equipment utilization by tracking their utilization time by areas where repurchasing of asset could be kept to a minimum through maximized use of the equipment, etc.

                                                             Figure by courtesy of Ekahau.

In this write-up, the standard wireless-based network 802.11 tracking technology is taken as a model for the function of real-time locating. Where the current hospital or institution wi-fi network already exists within the premises, it actually helps reduce the cost of implementation by piggy-back onto the existing wi-fi infrastructure. 

System Components

 Consisting of an positioning engine that runs on an application software to deliver the visibility of the assets and together with a web accessed Vision software and the required number of RFID active tags, the system with its multiple complex algorithms measures and verifies equipment location, location status over a single unified infrastructure. Active RFID tags wirelessly communicate with the positioning engine to determine the location, etc. 

Methodology

There are many methodology for performing range calculation and they include the following:

• Angle of Arrival;
• Time of Arrival;
• Time Difference of Arrival (TDOA);
• Received Signal Strength (RSS);
• Time of Flight (ToF);
• Symmetrical Double Sided Two Way Ranging (SDS-TWR). 

Linear Accelerator

Getting the Necessary Shielding Right

The use of heavy concrete or ordinary concrete in conjunction with steel to construct the primary barrier of the room is the basic design requirement leading to the construction of the safe facility meant for the use of the medical linear accelerator.

Concrete and Concrete Materials

Today heavy concrete are widely used method for the protection against radiations in Radiation Therapy. Traditionally, it has a limiting effect of heavy aggregates to the baryte gravels and sands. A considerable improvement in the characteristics has occurred, producing concrete with a much higher specific gravity, increasing the density from 3 to 4 if not more to 5.4 which can be realised. These new performance are necessary for widening the common use in radiation therapy.  

Concrete & Metal as a combination

If not carried out correctly, the metal layer could potentially result in a source of photoneutron production where it presents a problem of radiation exposure beyond its shield.  The problem resulting from photoneutron production in the shielding occurs only for the primary beam barriers and not for the secondary barriers. It becomes more pronounce for larger field. To do calculations of photoneutron production, it is necessary to fold the incident photon spectrum into the cross-section curve for photoneutron production as a function of photon energy. 

 

Assuming that bare iron or steel plate or slab is considered, and the neutron production from a lead plate of  1.8MeV for a 15MV x-ray beam to 2.2MeV for a 25MV x-ray beam, the neutron from an iron plate would have a lower average energy because of the high threshold energy. A conservative treatment is to consider 2.2MeV in all cases. If the metal is very thick, the neutron penetrating to the other side will be significantly degraded in energy. A significantly good example is to consider that all the neutrons are created in the first x-ray Tenth-Value-Layer (TVL) and then decrease the average energy in the remaining thickness accordingly to National Council on Radiation Protection recommendation.

The neutrons will be produced in circular areas, typically of the order of 4.5 meters and 3 meters away from the isocentre for the walls and ceilings, respectively. This yields radii of 137cm and 100cm respectively. They are nearly uniform sources, too large to treat as point sources when you are close to them.  At one meter, a lead plate would give a fluence-to-dose of 14 rem/week. For iron plate, it would give 1.7 rem/week. 

Clearly, the above present a true problem that must be alleviate in some manner. This can be accomplished by the use of some neutron shielding materials after or before the metal plate. Preferably one does both the options. Since the photoneutron production is isotropic, if the metal plate is on the inside surface of the room, the neutron will add a small amount of whole body neutron dose to the patient and a certain amount of room activation. X-ray shielding on the inside of the metal plate will virtually always be concrete. The neutron production will be decreased simply by the x-ray attenuation of the intervening concrete. The usual x-ray TVL's are adequate since pair production is not important in concrete.  Note the neutron dose inside the room is attenuated very fast with the inside concrete layer, since the neutron TVL's are less than half of the x-ray TVL's. One x-ray TVL of concrete inside the metal plate will decrease the neutron production by a factor of 10 and will attenuate the resultant neutrons by a factor of 100, in the point source approximation.