Thursday, July 12, 2007
2. Air emboli
3. Reservoir level
5. Concentration of the vitrification solution.
Computerized perfusion systems, have been around for decades, in the form of heart-lung machines. Though these may not turn out to be the ideal systems to build on, for vitrification perfusion, I think they are at least worth looking at. In speaking with people involved in cryonics, I’m not sure many people realize exactly what a heart-lung machine is, or does.
Typically, a heart-lung machine consists of 3-5 pumps that are monitored, and servo-controlled, by a computer. The computer is usually about the same size and shape as one of the pumps. The pumps, along with the computer are positioned on a rolling base that also accommodates a monitor, as well as holders for various perfusion components, (reservoirs, oxygenators, filters, etc.).
Cables are connected between the computer and the pumps. Desired parameters are entered into the computer. For instance, the computer can be set to alarm if pressure in a circuit exceeds 150mmHg, (or any other set value) and/or to turn off one of the pumps and clamp the associated lines, if the pressure in that pump’s circuit exceeds a higher value, (such as 200mmHg). Defaults for values such as these are simple to program, and easy to adjust, or override, during a case, if necessary.
The computer is not restricted to monitoring the perfusion circuit; you can monitor a variety of inputs such as patient temperatures and pressures.
There are pumps designed to deliver increasing/decreasing concentrations of certain solutions, such as the cardioplegia solutions used to stop the heart, during open-heart surgery. This may be of use, in the ramping of the vitrification solution concentration.
Someone who is familiar with Alcor has taken a lot of time to graciously explain to me why that company has approached their circuit the way they have. At this point, I feel they are doing what is best for their institution, given the history, their goals, their budget, and a few other factors. However, I think even they would agree that, if they were starting at “Square One,” and they could afford to write a check for a new heart-lung machine, they might take a different route.
I feel starting with a heart-lung machine that will measure, display and respond to four of the five desired parameters is a lot more practical than started from scratch. I have not priced heart-lung machines, recently, but I would estimate the cost of a new one with quite a few whistles and bells, to be in the neighborhood of 100,000K. That’s probably not as much as it would cost to have someone buy all the components and program a comparable system. Also, it is often possible to get used, or refurbished, models for much less. I think this course of action is at least worth exploring for companies that are just beginning to work toward the goal of vitrification.
***Please note: This article contains ideas and suggestions based on my education and my decade of experience as a clinical perfusionist in heart surgery. I have not participated in any cryonics procedures, and I have a lot to learn about the vitrification process. I am open to any, and all, constructive comments and criticisms.
Monday, July 9, 2007
The bus is described on the web site as a “Long-Range Transport Vehicle” for “distances of up to 1,000 miles.” This might work out in the event that someone at such a distance would call SA and say, “This client is imminently terminal, but you have at least two days to get here,” but that is highly unlikely to happen. If they had an emergency call from a client situated 1,000 miles away, would they drive approximately 20 hours to reach that client? If they made this choice, that client could possibly be well beyond “legally dead” by the time they arrived. If they were to get a call concerning a client who was located a long distance from their facility, they would most likely take their kits and fly to the location, in which case they should use a smaller vehicle that is easy to park, to transport their equipment to the airport.
In actuality, if such a distinction must be made, the bus is an excellent short-range vehicle. If SA had a case a short distance away, (up to several hundred miles), they could arrive there in this vehicle in less time than it would take them to get their personnel and equipment to the airport, and fly halfway across the country. With the proper development of this vehicle, SA could perform a washout and cooldown in the vehicle, eliminating the need to find a cooperative local mortuary.
This vehicle should be equipped with wide rear doors and a lift gate, as per my previous report on ramps. All relevant SA personnel have been in agreement that a lift gate is desirable; the possible addition of a lift gate is even mentioned on the SA web site. The plan Gary, Kelly and I agreed to at a management meeting following Platt's resignation, was as follows:
1. As soon as the Sprinter could be made ready to deploy, (Gary indicated this would a very short time), we would move all standby equipment from the bus to the Sprinter, so that the bus could be made ready for washout and cooldown procedures, as previously planned.
2. Gary was to research the purchase of a lift gate, (one that included the feature of backup manual operation), in the hopes of getting Saul’s approval to install a lift gate long before the conference in May 2007. The lift gate would be installed in-house, if approved.
In mentioning the possible addition of a lift gate, the SA web site states the rear door is “just tall enough to allow access by the ice bath with Thumper mounted across it,” but is it wide enough to accommodate loading a patient via a lift gate? This issue was to be addressed in Gary’s investigation of suitable lift gates.
In addition, though SA intended to use the Thumper, (along with massive quantities of pure oxygen), in this vehicle, the vehicle had no windows or other suitable ventilation source. After attention was called to this issue, Gary sealed up one of the Thumpers and built an exhaust system for it. (The Thumper has no built-in exhaust for the oxygen; the oxygen just leaks out through all the joints, seams and/or screw holes.) While this was an improvement, carrying two “H” cylinders of oxygen in the vehicles still seemed somewhat dangerous, especially in light of the sparking winch incident at a training session. In addition, standby team members don’t get a lot of practice, and might forget to connect the exhaust, and there is always the danger of a motor vehicle accident.
On the web site, the Dodge Sprinter is described as a “Short-Range Transport Vehicle” for “pickup and transport of patients over distances of 200 miles or less,” but it is really not suitable for transporting patients in need of washout and vitrification procedures, at any distance, as the vehicle is too small for even minimal intervention. Even if SA had a case within minutes of their facility, they may want to perform surgical procedures in the vehicle, and the Sprinter is simply not large enough for this, (see image, on SA's web site). They cannot assume the absence of delays in getting a patient to the facility or to a mortuary, so they should be prepared to provide care for the patient in the vehicle. The bus, which is equipped for procedures, is much more suitable for short-range cases, (see the second paragraph under the heading, “The Bus,” above, for further explanation).
Image of interior of Dodge Sprinter shows it is too small for procedures.
(Click on: “More... under image of Dodge Sprinter).
SA invested a lot of time and money for the design and installation of an LED lighting system, that required the hand-soldering of a rather large number of LEDs, for this vehicle. Though the designer of this lighting system, Charles Platt, has described it on one of the cryonics forums as "really cool," it is not only grossly inadequate, but the lighting effects are hideous. Additional lighting had to be installed after the completion of the LED system. Superior lighting, that would have been much less expensive, should have been purchased and installed, in the beginning.
The web site also states that “the Sprinter is not suitable for a lift gate powerful enough to raise our fully-loaded ice bath,” but this is inaccurate. TommyGate manufactures lift gates, specifically for this vehicle, that will lift up to 1,000 pounds. Whether this is desirable, or not, would depend on the intended future use of this vehicle.
The height of the vehicle has often been given as an advantage, but it seems more like a handicap. Again, the vehicle is far too small for procedures, so it’s unlikely the vehicle would be stationary, once the patient was loaded. Since the vehicle is really only suitable for transport, there is no need for personnel to stand up in the vehicle. (Imagine EMTs standing in an ambulance en route to a hospital.) If this vehicle were not as tall as it is, it would be ideal for rapidly deploying standby kits and personnel to an airport, but it is too tall to park in airport garages. (Platt's answer to this was they would leave the van at the curb and let it be towed.)
In discussing the cooldown and long-distance cryogenic transport of patients, the advantages of transporting patients in a vehicle, (rather than dealing with the transport issues and regulations associated with using commercial aircraft, or delivery services such as FedEx), was considered. The Sprinter might be suitable for this purpose. It’s comfortable and economical, and really not of much use in other capacities, once the build-out of the larger vehicle is completed. In addition, the use of the Sprinter for cryogenic transport would provide the added advantage of continuous patient monitoring by personnel in the vehicle, something that would be unavailable when using commercial shipping. SA should consider studies of the feasibility and projected cost of converting the Sprinter for cryogenic transport, and make comparisons to other methods of cryogenic shipping. If it is not suitable for cryogenic transport, it should be replaced with a van suitable for rapidly deploying standby equipment and personnel to the airport.
1. The ramp system requires too much space to deploy.
The ramp alone extends 9.5-feet from the side of the bus. Add to this the length of the PIB, (I believe that is 7-feet), the leveler and the person operating the leveler, and they are approaching 20-feet. Every time I addressed this issue with Platt, I received the response, “There is always a street corner, nearby.” The thought of parking the vehicle across an intersection, extending the ramp on the perpendicular street, and rolling the patient down the roadway in the PIB is absurd.
2. The leveler system is clumsy and unsafe.
During the in-house training session, even with several people working together, the PIB was seldom perfectly level. At times, one, or more, wheels were dangling off the side of the ramp. We had to back down the ramp and re-align the PIB, before continuing. If the person operating the leveler had slipped, some of the wheels would have missed the ramp and the PIB could have toppled over, spilling the contents.
The images on SA’s web site are misleading. I would guess that many shots were taken to get this series of photos that appear to be a flawless operation of the ramp/leveler/winch system. I also assume Charles had to constantly instruct Erico in the adjustment of the leveler, in order to keep the PIB level, as he was taking the photos. If we had an unedited video of the operation of the ramp system, it wouldn’t paint such a pretty picture. I would like to see Erico load the PIB, filled with a patient plus a couple hundred pounds of possibly fecally-contaminated ice water, by herself.
3. The winch is unsafe, especially when used in the presence of oxygen.
During one SA training session for the standby team members, the winch was sparking in the bus. The EMTs and paramedics got very upset thinking about the presence of large amounts of oxygen being used for the Thumper and ventilation. Charles said the emergency personnel were over-reacting; I say he was under-reacting. He said, “It was just a malfunction; Ken will fix it.” How can they guarantee there will never be another malfunction? They are working toward replacing the Thumper with the AutoPulse. This raises new issues in CPS, a topic which will be discussed here, sometime soon.
4. Using the ramp system contributes to the risk of medications and expensive equipment being dropped into the PIB.
Suspended Animation has a tray designed to rest across the top of the PIB. Anytime the PIB is not perfectly level, (and there will be times when it is not, when using the ramp system), they risk dropping medications and/or expensive equipment, from the tray into the ice and water.
5. A lot of time and money has been invested in the ramp/leveler/winch systems and they still do not perform as well as lift gates or PIBs with collapsible legs.
I believe if you add up the man-hours and materials, SA has far-exceeded the costs of lift gates, or a PIB with collapsible legs. At last count, they were on Platt’s third revision of the leveler design, and in my opinion, the performance was still unsatisfactory. The ramp systems are impractical and unsafe.
1. SA should have the proper doors and a lift gate installed on the bus, immediately.
When I suggested this, after Platt’s resignation, Gary Battiato of SA agreed with me. My suggestion included leaving the ramps as a backup system, but Battiato said we should make sure the new lift gates had manual backup systems and remove the ramps, altogether.
2. SA should either sell the Sprinter, or design a PIB with collapsible legs for it.
The Sprinter is too small to do procedures in, so I’m unsure of why the fact that it is “tall enough for people to stand up in” has been given as a rationale for the purchase of this vehicle. There’s a reason the gurney goes on the floor and the emergency personnel are seated, in emergency vehicles. It defies common sense to think about being able to stand, to take care of a patient in a moving vehicle.
This vehicle should be replaced with a van suitable for rushing standby personnel and equipment to the airport, and short enough to be parked in an airport garage, as this van is not.