Boris Gramatikov, PhD
PORTABLE PHYSIOLOGICAL SIGNAL PROCESSOR

FOR

A NOVEL PROGRAMMABLE CARDIAC MONITOR

PURPOSE OF THE PROJECT

The Biomedical Engineering Department of the Johns Hopkins University and DVP, Inc. of Rockville, MD, now InHand Electronics, Inc., have successfully competed and received a Phase II SBIR award from the NIH. The Phase II award to DVP was for developing a Portable Physiological Signal Processor (PSP), a novel device that allows flexible, programmable interface for digital signal processing in a portable unit.

The main purpose of the present project, supported by Maryland Industrial Partnerships Program (MIPS, Contract Agreement # 2209) is to create an innovative and commercially attractive product for cardiac monitoring. It is anticipated that this leveraged funding will allow us undertake the research on the new invention leading to a new product with exciting marketing potential and pave way for a more rapid access to commercialization.

The specific goal of this project is to develop a versatile, easily PROGRAMMABLE CARDIAC MONITOR (PCM) to be used in cardiological practices and for research. The project represents a collaboration between JHU and DVP, Inc.( InHand Electronics, Inc.). On behalf of Johns Hopkins, Dr. Boris Gramatikov is the person responsible for hardware and software development. Mr. Boris Donskoy is in charge on the DVP side. Here are the main issues of the collaboration project:

The two organizations will collaborate to commercialize the Programmable Cardiac Monitor technology. The long term goal is to develop the PCM based on the PSP technology [1,2]. This will lead to a generic signal processing technology and an ECG processing technology. The PSP will provide the hardware platform and signal processing tools. The PCM will provide ECG signal processing software validated for different medical applications. Each application does not necessarily depend on the others and may be financed and eventually manufactured separately. The PSP is expected to increase the marketing potential of the PCM.

A PSP prototype has already been developed [2]. The prototype included a motherboard (incl. ADC, DAC), and analog daughterboard, graphic LCD display (340x240 pixels) and a keypad. Two PCMCIA Type II slots are provided. One PCMCIA slot is intended to accept memory application cards. Two full duplex serial communication channels are provided. At present, work is aimed at expanding and improving the existing resources, to create a powerful, turnkey environment for the design of many different physiological instruments. The generic core of the earlier version of the PSP was a 16-bit Hitachi SH7032 RISC processor used as both a system controller and a signal processor [1].

The company is developing an extended version by adding the next generation of RISC technology [3], substantially increasing signal processing capabilities over the existing device. Further, a significant data logging capability is being added which will allow interface to a high capacity memory card or an ATA-type disk drive (through the PCMCIA slot). Such peripherals are currently commercially available in over 20 MB flash memories and 300 MB hard disk drives. These devices are relatively low in cost and, due to their current popularity, are expected to continue becoming more capable and less expensive.

Hardware development

The Daughter Board design was done by Dr. B. Gramatikov, JHU, and DVP, Inc (now InHand Electronics, Inc.), working in close collaboration. The design underwent several iterations on OrCad *.dsn file level. The board layout (6 layers, surface mounted technology) was carried out by Diversified Computer Services, Inc., who have specialized in multi-layer boards. After that, Quick Turn Circuits, Inc did board manufacturing and testing. Then, each partner, JHU and DVP, Inc, populated one daughter board and tested it.

Parallelizing of tasks:   To avoid unnecessary delay and to make the design more flexible, we decided to split the project into two parallel paths:

a) at JHU:

b) at DVP, Inc: Software and algorithms design The LabWindowsTM based software prototype was run together with the front-end module. Its main role till now, however, was to test the GUI and analysis algorithms. The software prototype shows the main controls, panels and functions, to be implemented on the portable Ischemia Monitor. Fifteen minutes of file e0103 of the ST-T data base were analyzed, with a documented mild episode of ST changes and transient ischemia at 12 min after start (100 mV = 1 mm are considered the treshold value). The ST trend plot clearly shows that, despite of a first peak which is an artefact. The newly devised mid-QRS High-frequency Index trend plot responded significantly better to this ischemic episode. The Time-Frequency distribution of the averaged QRS will be optional in the target device.

Recently DVP, Inc. decided to use Windows CE as a standard Operating System for the OmniMeter. This not only improves the graphical user interface, but also creates endless new opportunities such as adding TCP/IP interface (wireless or cable), Internet, Data Base Capabilities, Microsoft Office etc.

Check Boris Gramatikov's Home Page, JHU
 

Go to DVP, Inc, or now  InHand Electronics, Inc.

Some related publications:

[1] Girson, A., Donskoy, B.   Field-programmable instrument highlights application potential of RISC embedded controllersEDN, July 3, 1997, pp. 105-107.

[2] Gendreau, P.R.   Team creates PDA that morphs into many variations.   Portable Desig, July 1998, pp.49-56.

[3] Gendreau, P.R.   Spinning 2G configurable platforms challenges designers.   Portable Desig, August 1999, pp.41-46.