Technologies used in telecardiology are similar to those used in any other specialty that relies on a clinical physical exam to diagnose and treat patients via telehealth.
Transmission technologies are adequate if delivered at 128, 256, or 384 Kbps. Full T-1 bandwidth (1.5 Mbps) interactive video is not required to conduct adequate cardiology consultations for either new patient or follow-up visits. In a cost analysis of
telecardiology, a T1 line may not be feasible from a cost perspective unless shared by other services that produce higher utilization, revenue and/or expense reduction. Lower transmissions speeds degrade motion handling and a live exam may be more difficult.
However, the use of digital capture and rebuild built into may of the current transmission technologies as well as cameras preclude lower frame rates as being a barrier to
successful telecardiology. Equipment is specific to the service(s) provided. A
comprehensive analysis of equipment for a telecardiology service can be found at http://telehealth.hrsa.gov/pubs/tech/techhome.htm.
In a nutshell, telecardiology providers and recipients should determine technology needs in the areas outlined in the following table. The table represents a list of
equipment that is necessary for a telecardiology application, the use and function of the equipment, the features necessary, and pros and cons associated with each device.
Item Description/Characteristics Features Pertinent Purchase Issues with the video system come in several types but are usually a moderate grade of standard video conference cameras that meet the specifications outlined in the standards forMotion Video Systems – Main Camera. This camera is important in developing a sense of total patient condition, as the cardiology patient is a works well in most lighting situations, non-intrusive to the patient, easily problem solved for technical failure, can be used to communicate integrated patient conditions much better than hand held cameras, frees the operator to assist the patient
These cameras come in several different types with various options. While these cameras all provide video some will capture a still image and some will greatly magnify an area of the skin. The placement of the camera and need for
magnification will be directed by the cardiologist supervising the case.
Micro and Macro Lens Attachments
Video output to match the video input of the CODEC.
Excellent image and handheld
Expensive, magnification on some models may be too extreme for this specialty and add unnecessary additional
These cameras typically have a base and camera head much like an overhead projector.
They can be purchased with sidelights and base light (for transparencies). Some have a fixed focal length while others have a head that can be rotated for use as a second room camera. The patient presenter typically places the body part on the base and under the fixed camera, or rotates the camera head to display the image requested by the clinician.
Ability to show ECGs is excellent with immediate diagnostic capabilities In many cases the fixed tabletop unit makes it difficult to display lower torso images.
Expensive, should consider gooseneck or articulated arm model for this specialty
Item Description/Characteristics Features Pertinent Purchase
These cameras typically have a base that can be used with a tripod and a flexible head that can be positioned and maintained in a stationary position. They may or may not have auto focus. Because they are more flexible in terms of their placement they can be positioned to cover any part of the body.
Auto/Manual Focus
Auto White Balance Excellent image, Relatively Inexpensive, of manual dexterity on the part of operator
Cam-corder
Commercial or high-end consumer grade camcorders are sometimes used in place of a Patient Exam Camera. These cameras produce an excellent image, are easily zoomed, have auto focus and white balance, and can be handheld or tripod mounted. The clinician directs the presenter on where to focus, zoom or add light.
Camera These are basic digital cameras that capture images directly to disk or are downloadable to a PC. They are used in the same manner as a traditional 35mm camera.
Greater degree of attention to medicolegal aspects of store-and-forward electronic patient information required; and If correct lighting and/or angles are not captured the
cardiologist may not be able to interpret and may require that the patient return.
Video &
Still Image
Combination of the camcorder and digital camera gives the user the best of the video and still image world. This camera is preferred to a camcorder or digital camera as it integrates all applications into a flexible system that is adaptable and integratable to both clinical and technological situations. arteries, and the heart. Some stethoscopes work in-band and some only work out-of-band. Be sure to know the intended configuration prior to purchase.
The end-user should always try the technology prior to the ability to hear what is being transmitted.
If providing telecardiology consultations/encounters to patients, consider methodology, bandwidth, video input devices, video output devices, lighting, background/room color, audio input devices, audio output devices, stethoscopy requirements (in band or out-of-band), patient room configuration, consultant room configuration and methodology for transmitting information between the patient and the consultant. Since telecardiology is a service that most often is interview structured involving a moderate amount of gross physical inspection, with particular attention to auscultation of body structures including the heart, lungs, arteries and abdomen, these technical issues must be addressed.
Inspection of extremities and specific locations on the body of abnormal findings
indicating poor cardiac function are dependent on lighting and shadow creation and not necessarily high camera resolution. Any program considering telecardiology must demonstrate the proposed auscultation technology to the clinician who will be providing service to ensure the quality of range of tone and volume, as well as the ergonomics of the equipment, is acceptable to that clinician and others who may use the system.
If determining video input devices, consider that the standard integrated video cameras included with videoconference systems may be sufficient for much of the needs for physical exam. These are often high quality cameras that offer motorized pan/tilt/zoom capabilities and are very functional for full body images used while interviewing patients. These highly controllable cameras may sometimes be used for viewing integrated components of a physical exam such as chest expansion, full-length abdominal incisions, or both lower extremities. These cameras are typically reserved for fixed based video systems in telehealth applications and should be reserved for higher bandwidth systems.
A high quality camcorder for viewing a more targeted, detailed exam such as peripheral edema, jugular vein distention, etc. is optimum. These cameras are flexible and can be used to show areas of the patient when the patient cannot move well or for hard to reach areas such as the back or sacrum (edema assessment). Modern camcorders often have high capacity zoom lenses and work well in a variety of light conditions.
Electronic image stabilization and digitally freezing images are useful for removing motion artifacts.
A document camera (flat bed stand supporting a camera on a fixed arm) is a high quality camera used to show gross scale images on extremities, but they are difficult to manipulate to show all areas of the body. The base often has a built-in lighted view box to permit transmission of x-rays and ECGs or other hardcopy patient data (particularly patient logs or any written documents generated by the patient). Most of these cameras have power zoom controls, are auto-focus with manual focus override and have manual iris controls that work well in a variety of conditions. This extra equipment is only
necessary if radiographs are to be shown during the consult. Other text data may be viewed with a camcorder on a small 3 to 6 inch tripod.
ECHOCARDIOGRAPHY
A specific operational issue with respect to the implementation of telecardiology
services is whether or not echocardiography is a service to be provided within the scope of the telecardiology program. Echocardiography is a diagnostic test performed by a technician to study heart wall motion that results in ejection fraction, a determination of how well the heart is working. Tests are for adult and pediatric patients. Many sites have echocardiography machines already on site – others receive mobile echo services. Echocardiograms are usually scheduled, non-emergent, and non-urgent.
Although echocardiography can be done and is very useful in crisis situations, most telehealth echos are done as routine diagnostic procedures. There are two types of echos that can be transmitted over the telehealth network: taped echos and digital echos (real-time). Most echos are considered “store-and-forward” sessions. Taped echos are echos recorded through a standard VCR onto tape. This method of recording echos results in a 6-8% image loss which is acceptable for diagnostic purposes. The tape is viewed in the following manner: it is either played at the originating site on a VCR through the network and viewed by the cardiologist, or recorded again on a second tape to be viewed at a later time. In some cases the original VCR tape is also sent to the cardiologist for viewing on a standard VCR and monitor. Digital echos are recorded through a digital capture device which is a component or part of the
echocardiography unit. The digital echo is captured immediately with 100% image capture and is considered “real-time” for that reason. This image is then sent via
special modems over analogue phone lines or across a wide area network to a digital receiving station at the consultant site. The digital receiving station captures the image and stores it on an optical disc for viewing by the cardiologist at a later time. This system also allows the stored file to be retransmitted to any other receiving station with 100% image capture. The review stations are typically housed within the cardiologist’s PC. Some echo machines can be hooked directly to the CODEC or other switch device at the originating site in order to transmit a “live” echo to the provider. This configuration can also be used to transmit a “taped” echo, thus eliminating the need for the VCR. An additional benefit of a live echo is confirming the correct and enhanced placement of the probe for an individual patient. The cardiologist may have suggestions for a better picture that can be discussed and directed in a live consultation.
Technology needs for transmitting echos prior to, during, or after a telecardiology consult include:
1) VCR – The VCR used for echos can be a commercially available VCR, but it should be of high quality with emphasis on picture and sound quality and not accessory features. A four head machine is a minimum requirement. SVHS VCRs are optimum and must be placed in both the originating and consulting sites if used.
2) Tape – High quality VCR tape must be used to ensure integrity of the tape as well as resolution and sound quality. Commercially available tapes of high quality are acceptable. Packaging and storage of tapes is critical to ensure safe transfer of data from a technology standpoint as well as patient privacy.
3) Digital networks – These systems provide the best in image and sound transfer and are flexible in use and application. However, they are expensive and add an increased need for technology stations, receivers and viewers not found in most programs. The current telemedicine trend across the nation is to use tape and play the tape in-band in the network or send the tape to the consulting provider.
Technology is a tool for modern health care delivery. Telehealth consultations include technology that is totally foreign to most patients. When first hearing about telehealth, patients and providers often comment “that sounds real impersonal”. “How can the doctor tell what is wrong with me when he is 100 miles away?” “I like to get to know my patients well—how can I do that over a TV?” All sorts of unique challenges arise in establishing personal, caring relationships in this situation. The technology must be configured in a manner that minimizes its presence in the room and maximizes the patient’s attention on the provider. Locating microphones in the ceiling or in non-conspicuous places minimizes the patient’s shyness around microphones. Telehealth equipment should also be located at a level similar to what a patient would experience if they were seen in-person. Locations above forty-two inches from the bottom of the monitor place the equipment too high. Placing the equipment too low also distracts the patient unless the patient and provider would both be sitting in an in-person
consultation, such as Psychiatry. Using twenty-two inch monitors (or similar size) most closely resembles the size of the provider’s features (when framed properly) if the patient were being seen in-person. Configuring exam rooms as close as possible to what the patient would experience if being seen in person gives the patient a sense of familiarity and comfort. (Armstrong and Freuh, 2002; p.187).